ubuntu-cve-2026-45185
Vulnerability from osv_ubuntu
Published
2026-05-12 20:16
Modified
2026-06-04 00:16
Summary
Details

Exim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsing path. It is triggered when a client sends a TLS close_notify mid-body during a CHUNKING transfer, followed by a final cleartext byte on the same TCP connection. This can lead to heap corruption. An unauthenticated network attacker exploiting this vulnerability could execute arbitrary code.

Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
N/A (UNKNOWN)
high
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "exim4",
            "binary_version": "4.82-3ubuntu2.4+esm9"
          },
          {
            "binary_name": "exim4-base",
            "binary_version": "4.82-3ubuntu2.4+esm9"
          },
          {
            "binary_name": "exim4-config",
            "binary_version": "4.82-3ubuntu2.4+esm9"
          },
          {
            "binary_name": "exim4-daemon-heavy",
            "binary_version": "4.82-3ubuntu2.4+esm9"
          },
          {
            "binary_name": "exim4-daemon-light",
            "binary_version": "4.82-3ubuntu2.4+esm9"
          },
          {
            "binary_name": "eximon4",
            "binary_version": "4.82-3ubuntu2.4+esm9"
          }
        ],
        "priority_reason": "This results in remote code execution"
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:14.04:LTS",
        "name": "exim4",
        "purl": "pkg:deb/ubuntu/exim4@4.82-3ubuntu2.4+esm9?arch=source\u0026distro=esm-infra-legacy/trusty"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.80-7ubuntu3",
        "4.80-7ubuntu4",
        "4.80-9ubuntu1",
        "4.80-9ubuntu2",
        "4.82-3ubuntu1",
        "4.82-3ubuntu2",
        "4.82-3ubuntu2.1",
        "4.82-3ubuntu2.2",
        "4.82-3ubuntu2.3",
        "4.82-3ubuntu2.4",
        "4.82-3ubuntu2.4+esm1",
        "4.82-3ubuntu2.4+esm2",
        "4.82-3ubuntu2.4+esm3",
        "4.82-3ubuntu2.4+esm4",
        "4.82-3ubuntu2.4+esm6",
        "4.82-3ubuntu2.4+esm7",
        "4.82-3ubuntu2.4+esm8",
        "4.82-3ubuntu2.4+esm9"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "exim4",
            "binary_version": "4.86.2-2ubuntu2.6+esm9"
          },
          {
            "binary_name": "exim4-base",
            "binary_version": "4.86.2-2ubuntu2.6+esm9"
          },
          {
            "binary_name": "exim4-config",
            "binary_version": "4.86.2-2ubuntu2.6+esm9"
          },
          {
            "binary_name": "exim4-daemon-heavy",
            "binary_version": "4.86.2-2ubuntu2.6+esm9"
          },
          {
            "binary_name": "exim4-daemon-light",
            "binary_version": "4.86.2-2ubuntu2.6+esm9"
          },
          {
            "binary_name": "eximon4",
            "binary_version": "4.86.2-2ubuntu2.6+esm9"
          }
        ],
        "priority_reason": "This results in remote code execution"
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "exim4",
        "purl": "pkg:deb/ubuntu/exim4@4.86.2-2ubuntu2.6+esm9?arch=source\u0026distro=esm-infra-legacy/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.86-3ubuntu1",
        "4.86-7ubuntu1",
        "4.86-7ubuntu2",
        "4.86-7ubuntu3",
        "4.86.2-2ubuntu1",
        "4.86.2-2ubuntu2",
        "4.86.2-2ubuntu2.1",
        "4.86.2-2ubuntu2.2",
        "4.86.2-2ubuntu2.3",
        "4.86.2-2ubuntu2.4",
        "4.86.2-2ubuntu2.5",
        "4.86.2-2ubuntu2.6",
        "4.86.2-2ubuntu2.6+esm1",
        "4.86.2-2ubuntu2.6+esm2",
        "4.86.2-2ubuntu2.6+esm4",
        "4.86.2-2ubuntu2.6+esm5",
        "4.86.2-2ubuntu2.6+esm6",
        "4.86.2-2ubuntu2.6+esm7",
        "4.86.2-2ubuntu2.6+esm8",
        "4.86.2-2ubuntu2.6+esm9"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "exim4",
            "binary_version": "4.90.1-1ubuntu1.10+esm6"
          },
          {
            "binary_name": "exim4-base",
            "binary_version": "4.90.1-1ubuntu1.10+esm6"
          },
          {
            "binary_name": "exim4-config",
            "binary_version": "4.90.1-1ubuntu1.10+esm6"
          },
          {
            "binary_name": "exim4-daemon-heavy",
            "binary_version": "4.90.1-1ubuntu1.10+esm6"
          },
          {
            "binary_name": "exim4-daemon-light",
            "binary_version": "4.90.1-1ubuntu1.10+esm6"
          },
          {
            "binary_name": "eximon4",
            "binary_version": "4.90.1-1ubuntu1.10+esm6"
          }
        ],
        "priority_reason": "This results in remote code execution"
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "exim4",
        "purl": "pkg:deb/ubuntu/exim4@4.90.1-1ubuntu1.10+esm6?arch=source\u0026distro=esm-infra/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.89-5ubuntu1",
        "4.89-9ubuntu1",
        "4.89-9ubuntu2",
        "4.89-9ubuntu3",
        "4.89-9ubuntu4",
        "4.90.1-1ubuntu1",
        "4.90.1-1ubuntu1.1",
        "4.90.1-1ubuntu1.2",
        "4.90.1-1ubuntu1.3",
        "4.90.1-1ubuntu1.4",
        "4.90.1-1ubuntu1.5",
        "4.90.1-1ubuntu1.8",
        "4.90.1-1ubuntu1.9",
        "4.90.1-1ubuntu1.10",
        "4.90.1-1ubuntu1.10+esm1",
        "4.90.1-1ubuntu1.10+esm2",
        "4.90.1-1ubuntu1.10+esm3",
        "4.90.1-1ubuntu1.10+esm4",
        "4.90.1-1ubuntu1.10+esm5",
        "4.90.1-1ubuntu1.10+esm6"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "exim4",
            "binary_version": "4.93-13ubuntu1.12+esm1"
          },
          {
            "binary_name": "exim4-base",
            "binary_version": "4.93-13ubuntu1.12+esm1"
          },
          {
            "binary_name": "exim4-config",
            "binary_version": "4.93-13ubuntu1.12+esm1"
          },
          {
            "binary_name": "exim4-daemon-heavy",
            "binary_version": "4.93-13ubuntu1.12+esm1"
          },
          {
            "binary_name": "exim4-daemon-light",
            "binary_version": "4.93-13ubuntu1.12+esm1"
          },
          {
            "binary_name": "eximon4",
            "binary_version": "4.93-13ubuntu1.12+esm1"
          }
        ],
        "priority_reason": "This results in remote code execution"
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "exim4",
        "purl": "pkg:deb/ubuntu/exim4@4.93-13ubuntu1.12+esm1?arch=source\u0026distro=esm-infra/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.93-13ubuntu1.12+esm1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.92.1-1ubuntu3",
        "4.92.1-1ubuntu4",
        "4.93~RC2-1ubuntu1",
        "4.93-9ubuntu1",
        "4.93-11ubuntu1",
        "4.93-12ubuntu1",
        "4.93-13ubuntu1",
        "4.93-13ubuntu1.1",
        "4.93-13ubuntu1.5",
        "4.93-13ubuntu1.6",
        "4.93-13ubuntu1.7",
        "4.93-13ubuntu1.8",
        "4.93-13ubuntu1.9",
        "4.93-13ubuntu1.10",
        "4.93-13ubuntu1.11",
        "4.93-13ubuntu1.12"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "exim4",
            "binary_version": "4.95-4ubuntu2.8"
          },
          {
            "binary_name": "exim4-base",
            "binary_version": "4.95-4ubuntu2.8"
          },
          {
            "binary_name": "exim4-config",
            "binary_version": "4.95-4ubuntu2.8"
          },
          {
            "binary_name": "exim4-daemon-heavy",
            "binary_version": "4.95-4ubuntu2.8"
          },
          {
            "binary_name": "exim4-daemon-light",
            "binary_version": "4.95-4ubuntu2.8"
          },
          {
            "binary_name": "eximon4",
            "binary_version": "4.95-4ubuntu2.8"
          }
        ],
        "priority_reason": "This results in remote code execution"
      },
      "package": {
        "ecosystem": "Ubuntu:22.04:LTS",
        "name": "exim4",
        "purl": "pkg:deb/ubuntu/exim4@4.95-4ubuntu2.8?arch=source\u0026distro=jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.95-4ubuntu2.8"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.94.2-7ubuntu2",
        "4.95-2ubuntu2",
        "4.95-4ubuntu1",
        "4.95-4ubuntu2",
        "4.95-4ubuntu2.1",
        "4.95-4ubuntu2.2",
        "4.95-4ubuntu2.3",
        "4.95-4ubuntu2.4",
        "4.95-4ubuntu2.5",
        "4.95-4ubuntu2.6",
        "4.95-4ubuntu2.7"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "exim4",
            "binary_version": "4.97-4ubuntu4.5"
          },
          {
            "binary_name": "exim4-base",
            "binary_version": "4.97-4ubuntu4.5"
          },
          {
            "binary_name": "exim4-config",
            "binary_version": "4.97-4ubuntu4.5"
          },
          {
            "binary_name": "exim4-daemon-heavy",
            "binary_version": "4.97-4ubuntu4.5"
          },
          {
            "binary_name": "exim4-daemon-light",
            "binary_version": "4.97-4ubuntu4.5"
          },
          {
            "binary_name": "eximon4",
            "binary_version": "4.97-4ubuntu4.5"
          }
        ],
        "priority_reason": "This results in remote code execution"
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "exim4",
        "purl": "pkg:deb/ubuntu/exim4@4.97-4ubuntu4.5?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.97-4ubuntu4.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.96-17ubuntu2",
        "4.96-17ubuntu2.1",
        "4.97-3ubuntu1",
        "4.97-4ubuntu1",
        "4.97-4ubuntu3",
        "4.97-4ubuntu4",
        "4.97-4ubuntu4.1",
        "4.97-4ubuntu4.2",
        "4.97-4ubuntu4.3",
        "4.97-4ubuntu4.4"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "exim4",
            "binary_version": "4.98.2-1ubuntu2.2"
          },
          {
            "binary_name": "exim4-base",
            "binary_version": "4.98.2-1ubuntu2.2"
          },
          {
            "binary_name": "exim4-config",
            "binary_version": "4.98.2-1ubuntu2.2"
          },
          {
            "binary_name": "exim4-daemon-heavy",
            "binary_version": "4.98.2-1ubuntu2.2"
          },
          {
            "binary_name": "exim4-daemon-light",
            "binary_version": "4.98.2-1ubuntu2.2"
          },
          {
            "binary_name": "eximon4",
            "binary_version": "4.98.2-1ubuntu2.2"
          }
        ],
        "priority_reason": "This results in remote code execution"
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "exim4",
        "purl": "pkg:deb/ubuntu/exim4@4.98.2-1ubuntu2.2?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.98.2-1ubuntu2.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.98.1-1ubuntu2",
        "4.98.2-1ubuntu1",
        "4.98.2-1ubuntu2",
        "4.98.2-1ubuntu2.1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "exim4",
            "binary_version": "4.99.1-1ubuntu1.2"
          },
          {
            "binary_name": "exim4-base",
            "binary_version": "4.99.1-1ubuntu1.2"
          },
          {
            "binary_name": "exim4-config",
            "binary_version": "4.99.1-1ubuntu1.2"
          },
          {
            "binary_name": "exim4-daemon-heavy",
            "binary_version": "4.99.1-1ubuntu1.2"
          },
          {
            "binary_name": "exim4-daemon-light",
            "binary_version": "4.99.1-1ubuntu1.2"
          },
          {
            "binary_name": "eximon4",
            "binary_version": "4.99.1-1ubuntu1.2"
          }
        ],
        "priority_reason": "This results in remote code execution"
      },
      "package": {
        "ecosystem": "Ubuntu:26.04:LTS",
        "name": "exim4",
        "purl": "pkg:deb/ubuntu/exim4@4.99.1-1ubuntu1.2?arch=source\u0026distro=resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.99.1-1ubuntu1.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.98.2-1ubuntu2",
        "4.99-4ubuntu1",
        "4.99.1-1ubuntu1",
        "4.99.1-1ubuntu1.1"
      ]
    }
  ],
  "aliases": [],
  "details": "Exim before 4.99.3, in certain GnuTLS configurations, has a remotely reachable use-after-free in the BDAT body parsing path. It is triggered when a client sends a TLS close_notify mid-body during a CHUNKING transfer, followed by a final cleartext byte on the same TCP connection. This can lead to heap corruption. An unauthenticated network attacker exploiting this vulnerability could execute arbitrary code.",
  "id": "UBUNTU-CVE-2026-45185",
  "modified": "2026-06-04T00:16:53Z",
  "published": "2026-05-12T20:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-45185"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-45185"
    },
    {
      "type": "REPORT",
      "url": "https://xbow.com/blog/dead-letter-cve-2026-45185-xbow-found-rce-exim"
    },
    {
      "type": "REPORT",
      "url": "https://exim.org/static/doc/security/EXIM-Security-2026-05-01.1/EXIM-Security-2026-05-01.1.txt"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8270-1"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-8382-1"
    }
  ],
  "related": [
    "USN-8270-1",
    "USN-8382-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "high",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-45185"
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.