SB20260831115 - Ubuntu update for bind9
Published: August 31, 2026
Security Bulletin ID
SB20260831115
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Reachable assertion (CVE-ID: CVE-2026-13204)
CWE-ID: CWE-617 - Reachable Assertion
CVSSv4: 8.7 [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]
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.
Remediation
Install update from vendor's website.