Vulnerability-Lookup

ubuntu-cve-2026-40356

Vulnerability from osv_ubuntu

Published

2026-04-28 07:16

Modified

2026-08-05 09:14

Summary

Details

In MIT Kerberos 5 (aka krb5) before 1.22.3, there is an integer underflow and resultant out-of-bounds read if an application calls gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, possibly causing the process to terminate in parse_message.

Severity

5.9 (Medium)


                    
                      CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

7.5 (High)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-40356	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-40356	REPORT
	https://ubuntu.com/security/notices/USN-8585-1	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "krb5-admin-server",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-gss-samples",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-k5tls",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-kdc",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-kdc-ldap",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-kpropd",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-locales",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-multidev",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-otp",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-pkinit",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-user",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "libgssapi-krb5-2",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "libgssrpc4",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "libk5crypto3",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "libkadm5clnt-mit12",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "libkadm5srv-mit12",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "libkdb5-10",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "libkrad0",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "libkrb5-3",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "libkrb5support0",
            "binary_version": "1.19.2-2ubuntu0.8"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "krb5",
        "purl": "pkg:deb/ubuntu/krb5@1.19.2-2ubuntu0.8?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.19.2-2ubuntu0.8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.18.3-6",
        "1.18.3-7",
        "1.19.2-0ubuntu1",
        "1.19.2-1",
        "1.19.2-2",
        "1.19.2-2ubuntu0.1",
        "1.19.2-2ubuntu0.2",
        "1.19.2-2ubuntu0.3",
        "1.19.2-2ubuntu0.4",
        "1.19.2-2ubuntu0.5",
        "1.19.2-2ubuntu0.6",
        "1.19.2-2ubuntu0.7"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "krb5-admin-server",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-gss-samples",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-k5tls",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-kdc",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-kdc-ldap",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-kpropd",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-locales",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-multidev",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-otp",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-pkinit",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-user",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "libgssapi-krb5-2",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "libgssrpc4t64",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "libk5crypto3",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "libkadm5clnt-mit12",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "libkadm5srv-mit12",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "libkdb5-10t64",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "libkrad0",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "libkrb5-3",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "libkrb5support0",
            "binary_version": "1.20.1-6ubuntu2.7"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "krb5",
        "purl": "pkg:deb/ubuntu/krb5@1.20.1-6ubuntu2.7?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.20.1-6ubuntu2.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.20.1-3ubuntu1",
        "1.20.1-5build1",
        "1.20.1-6ubuntu1",
        "1.20.1-6ubuntu2",
        "1.20.1-6ubuntu2.1",
        "1.20.1-6ubuntu2.2",
        "1.20.1-6ubuntu2.3",
        "1.20.1-6ubuntu2.4",
        "1.20.1-6ubuntu2.5",
        "1.20.1-6ubuntu2.6"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "krb5-admin-server",
            "binary_version": "1.21.3-5ubuntu2"
          },
          {
            "binary_name": "krb5-gss-samples",
            "binary_version": "1.21.3-5ubuntu2"
          },
          {
            "binary_name": "krb5-k5tls",
            "binary_version": "1.21.3-5ubuntu2"
          },
          {
            "binary_name": "krb5-kdc",
            "binary_version": "1.21.3-5ubuntu2"
          },
          {
            "binary_name": "krb5-kdc-ldap",
            "binary_version": "1.21.3-5ubuntu2"
          },
          {
            "binary_name": "krb5-kpropd",
            "binary_version": "1.21.3-5ubuntu2"
          },
          {
            "binary_name": "krb5-locales",
            "binary_version": "1.21.3-5ubuntu2"
          },
          {
            "binary_name": "krb5-multidev",
            "binary_version": "1.21.3-5ubuntu2"
          },
          {
            "binary_name": "krb5-otp",
            "binary_version": "1.21.3-5ubuntu2"
          },
          {
            "binary_name": "krb5-pkinit",
            "binary_version": "1.21.3-5ubuntu2"
          },
          {
            "binary_name": "krb5-user",
            "binary_version": "1.21.3-5ubuntu2"
          },
          {
            "binary_name": "libgssapi-krb5-2",
            "binary_version": "1.21.3-5ubuntu2"
          },
          {
            "binary_name": "libgssrpc4t64",
            "binary_version": "1.21.3-5ubuntu2"
          },
          {
            "binary_name": "libk5crypto3",
            "binary_version": "1.21.3-5ubuntu2"
          },
          {
            "binary_name": "libkadm5clnt-mit12",
            "binary_version": "1.21.3-5ubuntu2"
          },
          {
            "binary_name": "libkadm5srv-mit12",
            "binary_version": "1.21.3-5ubuntu2"
          },
          {
            "binary_name": "libkdb5-10t64",
            "binary_version": "1.21.3-5ubuntu2"
          },
          {
            "binary_name": "libkrad0",
            "binary_version": "1.21.3-5ubuntu2"
          },
          {
            "binary_name": "libkrb5-3",
            "binary_version": "1.21.3-5ubuntu2"
          },
          {
            "binary_name": "libkrb5support0",
            "binary_version": "1.21.3-5ubuntu2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "krb5",
        "purl": "pkg:deb/ubuntu/krb5@1.21.3-5ubuntu2?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.21.3-4ubuntu2",
        "1.21.3-5ubuntu1",
        "1.21.3-5ubuntu2"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "krb5-admin-server",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-gss-samples",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-k5tls",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-kdc",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-kdc-ldap",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-kpropd",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-locales",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-multidev",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-otp",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-pkinit",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-user",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "libgssapi-krb5-2",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "libgssrpc4t64",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "libk5crypto3",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "libkadm5clnt-mit12",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "libkadm5srv-mit12",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "libkdb5-10t64",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "libkrad0",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "libkrb5-3",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "libkrb5support0",
            "binary_version": "1.22.1-2ubuntu4.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "krb5",
        "purl": "pkg:deb/ubuntu/krb5@1.22.1-2ubuntu4.1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.22.1-2ubuntu4.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.21.3-5ubuntu2",
        "1.22.1-2",
        "1.22.1-2ubuntu2",
        "1.22.1-2ubuntu3",
        "1.22.1-2ubuntu4"
      ]
    }
  ],
  "aliases": [],
  "details": "In MIT Kerberos 5 (aka krb5) before 1.22.3, there is an integer underflow and resultant out-of-bounds read if an application calls gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, possibly causing the process to terminate in parse_message.",
  "id": "UBUNTU-CVE-2026-40356",
  "modified": "2026-08-05T09:14:17Z",
  "published": "2026-04-28T07:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-40356"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-40356"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8585-1"
    }
  ],
  "related": [
    "USN-8585-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-40356"
  ]
}

CVE-2026-40356 (GCVE-0-2026-40356)

Vulnerability from cvelistv5 – Published: 2026-04-28 00:00 – Updated: 2026-04-28 13:10

Summary

Severity

5.9 (Medium)


                        
                          CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator (v2.0.3)

CWE

CWE-191 - Integer Underflow (Wrap or Wraparound)

Assigner

mitre

References

3 references

URL	Tags
https://web.mit.edu/kerberos/advisories/
https://cems.fun/2026/04/27/krb5-two-unauthentica…
https://github.com/krb5/krb5/commit/2e75f0d9362fb…

Impacted products

1 product

Vendor	Product	Version
MIT	Kerberos 5	Affected: 1.18 , < 1.22.3 (custom)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-40356",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-04-28T13:10:05.740836Z",
                "version": "2.0.3"
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          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
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          "product": "Kerberos 5",
          "vendor": "MIT",
          "versions": [
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              "status": "affected",
              "version": "1.18",
              "versionType": "custom"
            }
          ]
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      "cpeApplicability": [
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                  "criteria": "cpe:2.3:a:mit:kerberos_5:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "1.22.3",
                  "versionStartIncluding": "1.18",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In MIT Kerberos 5 (aka krb5) before 1.22.3, there is an integer underflow and resultant out-of-bounds read if an application calls gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, possibly causing the process to terminate in parse_message."
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      ],
      "metrics": [
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          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 5.9,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
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      "references": [
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        {
          "url": "https://cems.fun/2026/04/27/krb5-two-unauthenticated-network-vulnerabilities.html"
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  "cveMetadata": {
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    "assignerShortName": "mitre",
    "cveId": "CVE-2026-40356",
    "datePublished": "2026-04-28T00:00:00.000Z",
    "dateReserved": "2026-04-11T00:00:00.000Z",
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}

usn-8585-1

Vulnerability from osv_ubuntu

Published

2026-07-22 13:04

Modified

2026-07-22 13:04

Summary

krb5 vulnerabilities

Details

It was discovered that Kerberos had an integer underflow vulnerability in the berval2tl_data() function. An attacker could possibly use this issue to cause Kerberos to crash, resulting in a denial of service. (CVE-2026-11850)

It was discovered that Kerberos had vulnerabilities in its NegoEx mechanism parsing. A remote attacker could possibly use these issues to cause Kerberos to crash, resulting in a denial of service. (CVE-2026-40355, CVE-2026-40356)

References

URL

Type

	https://ubuntu.com/security/notices/USN-8585-1	ADVISORY
	https://ubuntu.com/security/CVE-2026-11850	REPORT
	https://ubuntu.com/security/CVE-2026-40355	REPORT
	https://ubuntu.com/security/CVE-2026-40356	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-11850",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-40355",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-40356",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:22.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "krb5-admin-server",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-gss-samples",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-k5tls",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-kdc",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-kdc-ldap",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-kpropd",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-locales",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-multidev",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-otp",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-pkinit",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "krb5-user",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "libgssapi-krb5-2",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "libgssrpc4",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "libk5crypto3",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "libkadm5clnt-mit12",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "libkadm5srv-mit12",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "libkdb5-10",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "libkrad0",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "libkrb5-3",
            "binary_version": "1.19.2-2ubuntu0.8"
          },
          {
            "binary_name": "libkrb5support0",
            "binary_version": "1.19.2-2ubuntu0.8"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "krb5",
        "purl": "pkg:deb/ubuntu/krb5@1.19.2-2ubuntu0.8?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.19.2-2ubuntu0.8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.18.3-6",
        "1.18.3-7",
        "1.19.2-0ubuntu1",
        "1.19.2-1",
        "1.19.2-2",
        "1.19.2-2ubuntu0.1",
        "1.19.2-2ubuntu0.2",
        "1.19.2-2ubuntu0.3",
        "1.19.2-2ubuntu0.4",
        "1.19.2-2ubuntu0.5",
        "1.19.2-2ubuntu0.6",
        "1.19.2-2ubuntu0.7"
      ]
    },
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-11850",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-40355",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-40356",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:24.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "krb5-admin-server",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-gss-samples",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-k5tls",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-kdc",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-kdc-ldap",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-kpropd",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-locales",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-multidev",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-otp",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-pkinit",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "krb5-user",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "libgssapi-krb5-2",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "libgssrpc4t64",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "libk5crypto3",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "libkadm5clnt-mit12",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "libkadm5srv-mit12",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "libkdb5-10t64",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "libkrad0",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "libkrb5-3",
            "binary_version": "1.20.1-6ubuntu2.7"
          },
          {
            "binary_name": "libkrb5support0",
            "binary_version": "1.20.1-6ubuntu2.7"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "krb5",
        "purl": "pkg:deb/ubuntu/krb5@1.20.1-6ubuntu2.7?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.20.1-6ubuntu2.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.20.1-3ubuntu1",
        "1.20.1-5build1",
        "1.20.1-6ubuntu1",
        "1.20.1-6ubuntu2",
        "1.20.1-6ubuntu2.1",
        "1.20.1-6ubuntu2.2",
        "1.20.1-6ubuntu2.3",
        "1.20.1-6ubuntu2.4",
        "1.20.1-6ubuntu2.5",
        "1.20.1-6ubuntu2.6"
      ]
    },
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2026-11850",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-40355",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            },
            {
              "id": "CVE-2026-40356",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:26.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "krb5-admin-server",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-gss-samples",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-k5tls",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-kdc",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-kdc-ldap",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-kpropd",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-locales",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-multidev",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-otp",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-pkinit",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "krb5-user",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "libgssapi-krb5-2",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "libgssrpc4t64",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "libk5crypto3",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "libkadm5clnt-mit12",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "libkadm5srv-mit12",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "libkdb5-10t64",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "libkrad0",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "libkrb5-3",
            "binary_version": "1.22.1-2ubuntu4.1"
          },
          {
            "binary_name": "libkrb5support0",
            "binary_version": "1.22.1-2ubuntu4.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "krb5",
        "purl": "pkg:deb/ubuntu/krb5@1.22.1-2ubuntu4.1?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.22.1-2ubuntu4.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.21.3-5ubuntu2",
        "1.22.1-2",
        "1.22.1-2ubuntu2",
        "1.22.1-2ubuntu3",
        "1.22.1-2ubuntu4"
      ]
    }
  ],
  "aliases": [],
  "details": "It was discovered that Kerberos had an integer underflow vulnerability\nin the berval2tl_data() function. An attacker could possibly use this issue\nto cause Kerberos to crash, resulting in a denial of service.\n(CVE-2026-11850)\n\nIt was discovered that Kerberos had vulnerabilities in its NegoEx mechanism\nparsing. A remote attacker could possibly use these issues to cause\nKerberos to crash, resulting in a denial of service. (CVE-2026-40355,\nCVE-2026-40356)",
  "id": "USN-8585-1",
  "modified": "2026-07-22T13:04:35Z",
  "published": "2026-07-22T13:04:35Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8585-1"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-11850"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-40355"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-40356"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "summary": "krb5 vulnerabilities",
  "upstream": [
    "UBUNTU-CVE-2026-11850",
    "UBUNTU-CVE-2026-40355",
    "UBUNTU-CVE-2026-40356"
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

ubuntu-cve-2026-40356

Vulnerability from osv_ubuntu

CVE-2026-40356 (GCVE-0-2026-40356)

usn-8585-1

Vulnerability from osv_ubuntu

Tags

Sightings

Nomenclature