Reachable assertion in ISC BIND - CVE-2026-13204
Published: July 23, 2026
Vulnerability identifier: #VU139207
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-2026-13204
CWE-ID: CWE-617
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 an assertion failure in the DNSSEC validation logic when validating a provably insecure domain covered by both an NSEC and NSEC3 record at the parent with an RRSIG for only one of these types. A remote attacker can provide crafted DNS data to cause a denial of service.
How to mitigate CVE-2026-13204
Install security update from vendor's website.