Improper Check for Unusual or Exceptional Conditions in ISC BIND - CVE-2026-12617
Published: July 23, 2026
Vulnerability identifier: #VU139208
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-12617
CWE-ID: CWE-754
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: ISC
Affected software:
ISC BIND
ISC BIND
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to improper handling of record ordering and response content in named resolver processing when processing responses to queries for CNAME or DNAME and A records. A remote attacker can send specially crafted DNS responses to cause a denial of service.
The issue is triggered when an authoritative server returns responses in a specific order, including delayed negative DNAME replies or a delayed self-referential CNAME reply.
How to mitigate CVE-2026-12617
Install security update from vendor's website.