CVE-2026-33337

Name	CVE-2026-33337
Description	Firebird is an open-source relational database management system. In versions prior to 5.0.4, 4.0.7 and 3.0.14, when deserializing a slice packet, the xdr_datum() function does not validate that a cstring length conforms to the slice descriptor bounds, allowing a cstring longer than the allocated buffer to overflow it. An unauthenticated attacker can exploit this by sending a crafted packet to the server, potentially causing a crash or other security impact. This issue has been fixed in versions 5.0.4, 4.0.7 and 3.0.14.
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
firebird3.0 (PTS)	bullseye	3.0.7.33374.ds4-2	vulnerable
	bullseye (security)	3.0.7.33374.ds4-2+deb11u1	vulnerable
	bookworm	3.0.11.33637.ds4-2+deb12u1	vulnerable
	trixie	3.0.12.ds7-13+deb13u1	vulnerable
	forky, sid	3.0.13.ds7-2	vulnerable
firebird4.0 (PTS)	trixie (security), trixie	4.0.5.3140.ds6-17+deb13u1	vulnerable
	forky, sid	4.0.6.3221.ds6-2	vulnerable

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
firebird3.0	source	(unstable)	(unfixed)
firebird4.0	source	(unstable)	(unfixed)

https://github.com/FirebirdSQL/firebird/security/advisories/GHSA-89mq-229g-x47p