Vulnerability in NLnet Labs NSD

[ Description ]Official description

NSD from version 4.13.0 has a heap use-after-free bug in logging errors on TLS connections, causing a crash of the server process, which can be triggered trivially by sending a DNS query over a DoT connection, and closing the connection without reading the response.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund29 Sep 2026WID-SEC-2026-3663

  OpenBSD: Multiple vulnerabilities Translated from German

  CVE-2026-12245CVE-2026-19401CVE-2026-18664+5 more CVEs

[ References ]References

• www.nlnetlabs.nl/downloads/nsd/CVE-2026-12245.txtvendor-advisory