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...

CVE-2026-33278

A flaw was discovered in Unbound’s DNSSEC validator can leave it using an invalid memory pointer after certain DS sub-query validations fail due to NSEC3 budget exhaustion. This may cause crashes and could potentially allow arbitrary code execution...

CVE-2026-33278 Possible arbitrary code execution during DNSSEC validation

NLnet Labs Unbound 1.19.1 up to and including version 1.25.0 has a vulnerability in the DNSSEC validator that enables denial of service and possible remote code execution as a result of deep copying a data structure and erroneously overwriting a destination pointer. An adversary can exploit the...

PT-2026-42125

Name of the Vulnerable Software and Affected Versions NLnet Labs Unbound versions 1.19.1 through 1.25.0 Description A flaw in the DNSSEC validator allows for denial of service and potential remote code execution. The issue occurs during the deep copying of a data structure when DS sub-queries...