GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2026-19667 (GCVE-0-2026-19667)

Vulnerability from cvelistv5 – Published: 2026-09-16 13:46 – Updated: 2026-09-16 13:46
VLAI
Title
Remote assertion failure via 16-bit length truncation in `dns_ncache_add()`
Summary
If an attacker-controlled authoritative server can produce a negative answer that is exactly 65536 bytes, then a flaw in `named` results in a negative cache entry of 0 bytes. When this entry is subsequently read, `named` aborts. 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
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
  • CWE-197 - Numeric Truncation Error
Assigner
References
Impacted products
Vendor Product Version CPE status
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:*:*:*:*:*:*:*:*
Create a notification for this product.
Date Public
2026-09-16 00:00
Credits
ISC would like to thank Rintaro Kawasugi for bringing this vulnerability to our attention.
Show details on NVD website
To clipboard 

{
  "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"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "ISC would like to thank Rintaro Kawasugi for bringing this vulnerability to our attention."
        }
      ],
      "datePublic": "2026-09-16T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "If an attacker-controlled authoritative server can produce a negative answer that is exactly 65536 bytes, then a flaw in `named` results in a negative cache entry of 0 bytes. When this entry is subsequently read, `named` aborts.\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": "We are not aware of any active exploits."
        }
      ],
      "impacts": [
        {
          "descriptions": [
            {
              "lang": "en",
              "value": "A successful attack results in unexpected program exit and a denial-of-service attack."
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-197",
              "description": "CWE-197 Numeric Truncation Error",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-16T13:46:56.783Z",
        "orgId": "404fd4d2-a609-4245-b543-2c944a302a22",
        "shortName": "isc"
      },
      "references": [
        {
          "name": "CVE-2026-19667",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://kb.isc.org/docs/cve-2026-19667"
        },
        {
          "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": "EXTERNAL"
      },
      "title": "Remote assertion failure via 16-bit length truncation in `dns_ncache_add()`",
      "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-2026-19667",
    "datePublished": "2026-09-16T13:46:56.783Z",
    "dateReserved": "2026-08-12T20:29:23.400Z",
    "dateUpdated": "2026-09-16T13:46:56.783Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-19667\",\"sourceIdentifier\":\"security-officer@isc.org\",\"published\":\"2026-09-16T14:17:05.037\",\"lastModified\":\"2026-09-16T19:27:00.080\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"If an attacker-controlled authoritative server can produce a negative answer that is exactly 65536 bytes, then a flaw in `named` results in a negative cache entry of 0 bytes. When this entry is subsequently read, `named` aborts.\\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.\"}],\"affected\":[{\"source\":\"security-officer@isc.org\",\"affectedData\":[{\"vendor\":\"ISC\",\"product\":\"BIND 9\",\"defaultStatus\":\"unaffected\",\"versions\":[{\"version\":\"9.11.0\",\"lessThanOrEqual\":\"9.18.50\",\"versionType\":\"custom\",\"status\":\"affected\"},{\"version\":\"9.20.0\",\"lessThanOrEqual\":\"9.20.27\",\"versionType\":\"custom\",\"status\":\"affected\"},{\"version\":\"9.21.0\",\"lessThanOrEqual\":\"9.21.25\",\"versionType\":\"custom\",\"status\":\"affected\"},{\"version\":\"9.11.3-S1\",\"lessThanOrEqual\":\"9.18.50-S1\",\"versionType\":\"custom\",\"status\":\"affected\"},{\"version\":\"9.20.9-S1\",\"lessThanOrEqual\":\"9.20.27-S1\",\"versionType\":\"custom\",\"status\":\"affected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-officer@isc.org\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"NONE\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"security-officer@isc.org\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-197\"}]}],\"references\":[{\"url\":\"https://downloads.isc.org/isc/bind9/9.20.29\",\"source\":\"security-officer@isc.org\"},{\"url\":\"https://downloads.isc.org/isc/bind9/9.21.26\",\"source\":\"security-officer@isc.org\"},{\"url\":\"https://kb.isc.org/docs/cve-2026-19667\",\"source\":\"security-officer@isc.org\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Important",
      "current_release_date": "2026-09-17T04:31:42+00:00",
      "cve": "CVE-2026-19667",
      "id": "CVE-2026-19667",
      "initial_release_date": "2026-09-16T13:46:56.783000+00:00",
      "product_status:known_affected": "74",
      "product_status:known_not_affected": "12",
      "product_status:under_investigation": "2",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "bind9: bind: BIND 9: Denial of Service via 16-bit length truncation in DNS negative cache handling",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-19667.json",
      "version": "3"
    }
  }
}



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.


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.