CVE-2025-5268

Name	CVE-2025-5268
Description	Memory safety bugs present in Firefox 138, Thunderbird 138, Firefox ESR 128.10, and Thunderbird 128.10. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 139 and Firefox ESR < 128.11.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DLA-4191-1, DLA-4194-1, DSA-5926-1, DSA-5932-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
firefox (PTS)	sid	139.0-1	fixed
firefox-esr (PTS)	bullseye	115.14.0esr-1~deb11u1	vulnerable
	bullseye (security)	128.11.0esr-1~deb11u1	fixed
	bookworm	128.10.0esr-1~deb12u1	vulnerable
	bookworm (security)	128.11.0esr-1~deb12u1	fixed
	trixie, sid	128.11.0esr-1	fixed
thunderbird (PTS)	bullseye	1:115.12.0-1~deb11u1	vulnerable
	bullseye (security)	1:128.11.0esr-1~deb11u1	fixed
	bookworm	1:128.10.0esr-1~deb12u1	vulnerable
	bookworm (security)	1:128.11.0esr-1~deb12u1	fixed
	trixie	1:128.10.0esr-1	vulnerable
	sid	1:128.11.0esr-1	fixed

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

Package	Type	Release	Fixed Version	Origin
firefox	source	(unstable)	139.0-1
firefox-esr	source	bullseye	128.11.0esr-1~deb11u1	DLA-4191-1
firefox-esr	source	bookworm	128.11.0esr-1~deb12u1	DSA-5926-1
firefox-esr	source	(unstable)	128.11.0esr-1
thunderbird	source	bullseye	1:128.11.0esr-1~deb11u1	DLA-4194-1
thunderbird	source	bookworm	1:128.11.0esr-1~deb12u1	DSA-5932-1
thunderbird	source	(unstable)	1:128.11.0esr-1

Notes

https://www.mozilla.org/en-US/security/advisories/mfsa2025-42/#CVE-2025-5268
https://www.mozilla.org/en-US/security/advisories/mfsa2025-44/#CVE-2025-5268
https://www.mozilla.org/en-US/security/advisories/mfsa2025-46/#CVE-2025-5268