Vulnerability in NLnet Labs NSD

[ Description ]Official description

Tokens of text in RDATA (of for example TXT records) under 32 bytes are not checked to stay within the space reserved for the RDATA allowing for arbitrary sized out of bound stack writes, including an overwrite of a callback function pointer which is called directly after parse. Zone files which are written out by NSD itself, such for zones for which the NSD instance is secondary, will not be formatted like this. The zone file must be fed to NSD directly, (but it could come, for example, from an operator controlled provisioning system).

[ 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-Bund19 Oct 2026WID-SEC-2026-4044

  OpenBSD: Multiple vulnerabilities Translated from German

  CVE-2026-101341CVE-2026-101337CVE-2026-101338+1 more CVEs

[ References ]References

• www.nlnetlabs.nl/downloads/nsd/CVE-2026-101341.txt