Vulnerability-Lookup

GHSA-38FX-CM5X-27PG

Vulnerability from github – Published: 2026-09-16 15:31 – Updated: 2026-09-16 15:31

Details

An inapplicable NSEC record may be accepted by a named resolver as proof that no wildcard exists, which could allow an attacker at the same or an upstream level of the zone name to mask the existence of a victim's wildcard record. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.

Severity

5.9 (Medium)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2026-19941"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-345"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-16T14:17:05Z",
    "severity": "MODERATE"
  },
  "details": "An inapplicable NSEC record may be accepted by a `named` resolver as proof that no wildcard exists, which could allow an attacker at the same or an upstream level of the zone name to mask the existence of a victim\u0027s wildcard record.\nThis issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.",
  "id": "GHSA-38fx-cm5x-27pg",
  "modified": "2026-09-16T15:31:10Z",
  "published": "2026-09-16T15:31:10Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-19941"
    },
    {
      "type": "WEB",
      "url": "https://downloads.isc.org/isc/bind9/9.20.29"
    },
    {
      "type": "WEB",
      "url": "https://downloads.isc.org/isc/bind9/9.21.26"
    },
    {
      "type": "WEB",
      "url": "https://kb.isc.org/docs/cve-2026-19941"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-19941 (GCVE-0-2026-19941)

Vulnerability from cvelistv5 – Published: 2026-09-16 13:52 – Updated: 2026-09-16 13:52

Title

checkwildcard() accepts an out-of-zone NSEC as a wildcard-nonexistence proof

Summary

An inapplicable NSEC record may be accepted by a `named` resolver as proof that no wildcard exists, which could allow an attacker at the same or an upstream level of the zone name to mask the existence of a victim's wildcard record. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.

Severity

5.9 (Medium)


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

CWE

CWE-345 - Insufficient Verification of Data Authenticity

Assigner

isc mitre root

References

3 references

URL	Tags
https://kb.isc.org/docs/cve-2026-19941	vendor-advisory
https://downloads.isc.org/isc/bind9/9.20.29	patch
https://downloads.isc.org/isc/bind9/9.21.26	patch

Impacted products

1 product

Vendor	Product	Version
ISC	BIND 9	Affected: 9.11.0 , ≤ 9.18.50 (custom) Affected: 9.20.0 , ≤ 9.20.27 (custom) Affected: 9.21.0 , ≤ 9.21.25 (custom) Affected: 9.11.3-S1 , ≤ 9.18.50-S1 (custom) Affected: 9.20.9-S1 , ≤ 9.20.27-S1 (custom) cpe:2.3:a:isc:bind:::::::: cpe:2.3:a:isc:bind:::::::: cpe:2.3:a:isc:bind:::::::: cpe:2.3:a:isc:bind:::::::: cpe:2.3:a:isc:bind::::::::

Date Public

2026-09-16 00:00

Show details on NVD website

JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "BIND 9",
          "vendor": "ISC",
          "versions": [
            {
              "lessThanOrEqual": "9.18.50",
              "status": "affected",
              "version": "9.11.0",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "9.20.27",
              "status": "affected",
              "version": "9.20.0",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "9.21.25",
              "status": "affected",
              "version": "9.21.0",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "9.18.50-S1",
              "status": "affected",
              "version": "9.11.3-S1",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "9.20.27-S1",
              "status": "affected",
              "version": "9.20.9-S1",
              "versionType": "custom"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
                  "versionEndIncluding": "9.18.50",
                  "versionStartIncluding": "9.11.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
                  "versionEndIncluding": "9.20.27",
                  "versionStartIncluding": "9.20.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
                  "versionEndIncluding": "9.21.25",
                  "versionStartIncluding": "9.21.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
                  "versionEndIncluding": "9.18.50-S1",
                  "versionStartIncluding": "9.11.3-S1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*",
                  "versionEndIncluding": "9.20.27-S1",
                  "versionStartIncluding": "9.20.9-S1",
                  "vulnerable": true
                }
              ],
              "operator": "OR"
            }
          ]
        }
      ],
      "datePublic": "2026-09-16T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "An inapplicable NSEC record may be accepted by a `named` resolver as proof that no wildcard exists, which could allow an attacker at the same or an upstream level of the zone name to mask the existence of a victim\u0027s wildcard record.\nThis issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1."
        }
      ],
      "exploits": [
        {
          "lang": "en",
          "value": "This flaw was discovered in internal testing. We are not aware of any active exploits."
        }
      ],
      "impacts": [
        {
          "descriptions": [
            {
              "lang": "en",
              "value": "An attacker at the same or an upstream zone name may be able to deny the existence of a wildcard mapping thus resulting in a cache poisoning attack."
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.9,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-345",
              "description": "CWE-345 Insufficient Verification of Data Authenticity",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-16T13:52:49.400Z",
        "orgId": "404fd4d2-a609-4245-b543-2c944a302a22",
        "shortName": "isc"
      },
      "references": [
        {
          "name": "CVE-2026-19941",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://kb.isc.org/docs/cve-2026-19941"
        },
        {
          "tags": [
            "patch"
          ],
          "url": "https://downloads.isc.org/isc/bind9/9.20.29"
        },
        {
          "tags": [
            "patch"
          ],
          "url": "https://downloads.isc.org/isc/bind9/9.21.26"
        }
      ],
      "solutions": [
        {
          "lang": "en",
          "value": "Upgrade to the patched release most closely related to your current version of BIND 9: 9.20.29, 9.21.26, or 9.20.29-S1."
        }
      ],
      "source": {
        "discovery": "INTERNAL"
      },
      "title": "checkwildcard() accepts an out-of-zone NSEC as a wildcard-nonexistence proof",
      "workarounds": [
        {
          "lang": "en",
          "value": "No workarounds known."
        }
      ],
      "x_generator": {
        "engine": "cvelib 1.8.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "404fd4d2-a609-4245-b543-2c944a302a22",
    "assignerShortName": "isc",
    "cveId": "CVE-2026-19941",
    "datePublished": "2026-09-16T13:52:49.400Z",
    "dateReserved": "2026-08-15T14:30:38.165Z",
    "dateUpdated": "2026-09-16T13:52:49.400Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.