CVE-2026-12244

Name	CVE-2026-12244
Description	If NSD is configured as secondary for a zone, the primary of that zone can crash NSD with an AXFR containing a DNS message with a special crafted SVCB RR with an rdata size of 65512, that let's an (uint16_t) variable that is used to allocate space needed for the RR wrap (because total size > 65535), causing a heap overflow. The attacker can perform a controlled (RCE class) head write of up to 65509 bytes
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
nsd (PTS)	bullseye	4.3.5-1	fixed
	bookworm	4.6.1-1	fixed
	trixie	4.12.0-1	fixed
	forky, sid	4.15.0-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version
nsd	source	bullseye	(not affected)
nsd	source	bookworm	(not affected)
nsd	source	trixie	(not affected)
nsd	source	(unstable)	4.14.3-1

Notes

[trixie] - nsd <not-affected> (Vulnerable code introduced later)
[bookworm] - nsd <not-affected> (Vulnerable code introduced later)
[bullseye] - nsd <not-affected> (Vulnerable code introduced later)
https://www.nlnetlabs.nl/downloads/nsd/CVE-2026-12244.txt