CVE-2026-12617
Record ordering based unexpected exit with CNAME or DNAME
Description
The issue is unexpected program termination based on ordering and/or specific content in responses to queries for CNAME or DNAME, and A records. Specifically, if a client queries for a DNAME and A record below the DNAME to the resolver, and the authoritative server responds positively to the A query but delays the DNAME response and later responds negatively, `named` may quit unexpectedly. Or, if a client queries for a CNAME and A record for the same name to the resolver, and the authoritative server responds positively to the A query but delays the CNAME response and later responds with a self-referential CNAME, the same failure may occur. This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.24, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.
INFO
Published Date :
July 22, 2026, 3:16 p.m.
Last Modified :
Nov. 2, 2026, 4:28 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update BIND 9 to a non-vulnerable version.
- Apply vendor-provided patches.
- Restart the BIND service.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-12617.
| URL | Resource |
|---|---|
| https://downloads.isc.org/isc/bind9/9.20.26 | Product |
| https://kb.isc.org/docs/cve-2026-12617 | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-12617 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-12617
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-12617 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-12617 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Nov. 02, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:* versions from (including) 9.18.0 up to (including) 9.18.50 *cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:* versions from (including) 9.20.0 up to (including) 9.20.24 *cpe:2.3:a:isc:bind:*:*:*:*:supported_preview:*:*:* versions from (including) 9.18.11 up to (including) 9.18.50 *cpe:2.3:a:isc:bind:*:*:*:*:supported_preview:*:*:* versions from (including) 9.20.9 up to (including) 9.20.24 Added Reference Type Internet Systems Consortium (ISC): https://downloads.isc.org/isc/bind9/9.20.26 Types: Product Added Reference Type Internet Systems Consortium (ISC): https://kb.isc.org/docs/cve-2026-12617 Types: Vendor Advisory -
CVE Translated by [email protected]
Oct. 24, 2026
Action Type Old Value New Value Added Translation Title: BIND 9 de ISC, Description: El problema es la terminación inesperada del programa basada en el orden y/o el contenido específico en las respuestas a las consultas de registros CNAME o DNAME, y registros A. Específicamente, si un cliente consulta por un registro DNAME y un registro A por debajo del DNAME al resolvedor, y el servidor autoritativo responde positivamente a la consulta A pero retrasa la respuesta DNAME y luego responde negativamente, ’named’ puede cerrarse inesperadamente. O, si un cliente consulta por un registro CNAME y un registro A para el mismo nombre al resolvedor, y el servidor autoritativo responde positivamente a la consulta A pero retrasa la respuesta CNAME y luego responde con un CNAME autorreferencial, la misma falla puede ocurrir. Este problema afecta a las versiones de BIND 9 9.18.0 a 9.18.50, 9.20.0 a 9.20.24, 9.18.11-S1 a 9.18.50-S1, y 9.20.9-S1 a 9.20.24-S1. -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 22, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-12617', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-07-22T18:48:06.430818Z'} -
New CVE Received by [email protected]
Jul. 22, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'ISC', 'product': 'BIND 9', 'versions': [{'status': 'affected', 'version': '9.18.0', 'versionType': 'custom', 'lessThanOrEqual': '9.18.50'}, {'status': 'affected', 'version': '9.20.0', 'versionType': 'custom', 'lessThanOrEqual': '9.20.24'}, {'status': 'affected', 'version': '9.18.11-S1', 'versionType': 'custom', 'lessThanOrEqual': '9.18.50-S1'}, {'status': 'affected', 'version': '9.20.9-S1', 'versionType': 'custom', 'lessThanOrEqual': '9.20.24-S1'}], 'defaultStatus': 'unaffected'}] Added Description The issue is unexpected program termination based on ordering and/or specific content in responses to queries for CNAME or DNAME, and A records. Specifically, if a client queries for a DNAME and A record below the DNAME to the resolver, and the authoritative server responds positively to the A query but delays the DNAME response and later responds negatively, `named` may quit unexpectedly. Or, if a client queries for a CNAME and A record for the same name to the resolver, and the authoritative server responds positively to the A query but delays the CNAME response and later responds with a self-referential CNAME, the same failure may occur. This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.24, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CWE CWE-617 Added Reference https://downloads.isc.org/isc/bind9/9.20.26 Added Reference https://kb.isc.org/docs/cve-2026-12617