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...

CVE-2026-42959 Crash during DNSSEC validation of malicious content

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 Crash during DNSSEC validation of malicious content

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

CVE-2026-42959 affects NLnet Labs Unbound up to version 1.25.0. The vulnerability lies in the DNSSEC validator: while constructing chase-reply messages, the code uses the wrong counter to calculate write offsets for ADDITIONAL section rrsets. This, combined with DNAME duplication increasing the A...