CVE-2026-12617

Publication date 22 July 2026

Last updated 6 August 2026


Ubuntu priority

Cvss 3 Severity Score

7.5 · High

Score breakdown

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.

Read the notes from the security team

Status

Package Ubuntu Release Status
bind9 26.04 LTS resolute
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation
16.04 LTS xenial
Needs evaluation
14.04 LTS trusty
Needs evaluation
isc-dhcp 26.04 LTS resolute
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy
Not affected
20.04 LTS focal
Not affected
18.04 LTS bionic
Needs evaluation
16.04 LTS xenial
Not affected
14.04 LTS trusty
Not affected
bind9-libs 26.04 LTS resolute Not in release
24.04 LTS noble Not in release
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation

Notes


alexmurray

As of isc-dhcp-4.4.3-1, isc-dhcp vendors bind9 libs


mdeslaur

in focal and jammy, isc-dhcp uses the bind9-libs package

Severity score breakdown

CVSS version: CVSS v3.0

Base score 7.5 · High

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


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