K000163141: NLnet Labs Unbound vulnerability CVE-2026-42959

Security Advisory Description NLnet Labs Unbound up to and including version 1.25.0 has a denial of service vulnerability in the DNSSEC validator that can lead to a crash given malicious upstream replies. When Unbound constructs chase-reply messages for validation, the code uses the wrong counter...

unbound: Unbound DNSSEC Validator Denial of Service via Incorrect Write Offset Counter in Chase-Reply Messages

A flaw was found in Unbound's DNSSEC validator when constructing chase-reply messages for validation. The code uses the wrong counter to calculate write offsets for ADDITIONAL section resource record sets. When a DNAME chain is combined with authority filtering, an uninitialized array slot is...

CVE-2026-42959

A flaw was found in Unbound's DNSSEC validator when constructing chase-reply messages for validation. The code uses the wrong counter to calculate write offsets for ADDITIONAL section resource record sets. When a DNAME chain is combined with authority filtering, an uninitialized array slot is...

AZL-87021 CVE-2026-42959 affecting package unbound for versions less than 1.25.1-1

NLnet Labs Unbound up to and including version 1.25.0 has a denial of service vulnerability in the DNSSEC validator that can lead to a crash given malicious upstream replies. When Unbound constructs chase-reply messages for validation, the code uses the wrong counter to calculate write offsets fo...

CVE-2026-42959

NLnet Labs Unbound up to and including version 1.25.0 has a denial of service vulnerability in the DNSSEC validator that can lead to a crash given malicious upstream replies. When Unbound constructs chase-reply messages for validation, the code uses the wrong counter to calculate write offsets fo...

PT-2026-42132

Name of the Vulnerable Software and Affected Versions NLnet Labs Unbound versions prior to 1.25.1 Description A denial of service issue exists in the DNSSEC validator. When constructing chase-reply messages for validation, the software uses an incorrect counter to calculate write offsets for...