CVE-2026-27821

Name	CVE-2026-27821
Description	GPAC is an open-source multimedia framework. In versions up to and including 26.02.0, a stack buffer overflow occurs during NHML file parsing in `src/filters/dmx_nhml.c`. The value of the xmlHeaderEnd XML attribute is copied from att->value into szXmlHeaderEnd[1000] using strcpy() without any length validation. If the input exceeds 1000 bytes, it overwrites beyond the stack buffer boundary. Commit 9bd7137fded2db40de61a2cf3045812c8741ec52 patches the issue.
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
gpac (PTS)	bullseye (security), bullseye	1.0.1+dfsg1-4+deb11u3	vulnerable

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
gpac	source	bullseye	(unfixed)	end-of-life
gpac	source	(unstable)	(unfixed)

Notes

[bullseye] - gpac <end-of-life> (EOLed in debian-security-support)
https://github.com/gpac/gpac/security/advisories/GHSA-q7qh-8r2r-q559
https://github.com/gpac/gpac/commit/9bd7137fded2db40de61a2cf3045812c8741ec52