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CVE-2026-19666 (GCVE-0-2026-19666)

Vulnerability from cvelistv5 – Published: 2026-09-16 14:02 – Updated: 2026-09-16 14:02
VLAI
Title
Use-after-free in query_addnoqnameproof() via the DNS64 filter64 path
Summary
On a resolver configured to use ``dns64``, if an applicable answer from the authoritative server is malformed in a specific way, the resolver `named` process will exit unexpectedly. 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
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 

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          "vendor": "ISC",
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      "descriptions": [
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      "exploits": [
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          "value": "We are not aware of any active exploits."
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            "attackVector": "NETWORK",
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            "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"
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      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-416",
              "description": "CWE-416 Use After Free",
              "lang": "en",
              "type": "CWE"
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      "providerMetadata": {
        "dateUpdated": "2026-09-16T14:02:30.453Z",
        "orgId": "404fd4d2-a609-4245-b543-2c944a302a22",
        "shortName": "isc"
      },
      "references": [
        {
          "name": "CVE-2026-19666",
          "tags": [
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          "url": "https://kb.isc.org/docs/cve-2026-19666"
        },
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          "tags": [
            "patch"
          ],
          "url": "https://downloads.isc.org/isc/bind9/9.20.29"
        },
        {
          "tags": [
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          "url": "https://downloads.isc.org/isc/bind9/9.21.26"
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      "solutions": [
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          "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": "Use-after-free in query_addnoqnameproof() via the DNS64 filter64 path",
      "workarounds": [
        {
          "lang": "en",
          "value": "No workarounds known."
        }
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    "datePublished": "2026-09-16T14:02:30.453Z",
    "dateReserved": "2026-08-12T20:26:23.829Z",
    "dateUpdated": "2026-09-16T14:02:30.453Z",
    "state": "PUBLISHED"
  },
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    "redhat_vex": {
      "aggregate_severity": "Important",
      "current_release_date": "2026-09-17T10:10:47+00:00",
      "cve": "CVE-2026-19666",
      "id": "CVE-2026-19666",
      "initial_release_date": "2026-09-16T14:02:30.453000+00:00",
      "product_status:known_affected": "76",
      "product_status:known_not_affected": "12",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "bind: BIND: Denial of Service via malformed DNS64 responses",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-19666.json",
      "version": "3"
    }
  }
}



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