CVE-2025-8027

Name	CVE-2025-8027
Description	On 64-bit platforms IonMonkey-JIT only wrote 32 bits of the 64-bit return value space on the stack. Baseline-JIT, however, read the entire 64 bits. This vulnerability affects Firefox < 141, Firefox ESR < 115.26, Firefox ESR < 128.13, Firefox ESR < 140.1, Thunderbird < 141, Thunderbird < 128.13, and Thunderbird < 140.1.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DLA-4250-1, DLA-4253-1, DSA-5964-1, DSA-5966-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
firefox (PTS)	sid	143.0-1	fixed
firefox-esr (PTS)	bullseye	115.14.0esr-1~deb11u1	vulnerable
	bullseye (security)	128.14.0esr-1~deb11u1	fixed
	bookworm, bookworm (security)	128.14.0esr-1~deb12u1	fixed
	trixie (security), trixie	128.14.0esr-1~deb13u1	fixed
	forky	128.14.0esr-1	fixed
	sid	140.3.0esr-1	fixed
thunderbird (PTS)	bullseye	1:115.12.0-1~deb11u1	vulnerable
	bullseye (security)	1:128.14.0esr-1~deb11u1	fixed
	bookworm, bookworm (security)	1:128.14.0esr-1~deb12u1	fixed
	trixie (security), trixie	1:128.14.0esr-1~deb13u1	fixed
	forky, sid	1:128.14.0esr-1	fixed

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

Package	Type	Release	Fixed Version	Origin
firefox	source	(unstable)	141.0-1
firefox-esr	source	bullseye	128.13.0esr-1~deb11u1	DLA-4250-1
firefox-esr	source	bookworm	128.13.0esr-1~deb12u1	DSA-5964-1
firefox-esr	source	(unstable)	128.13.0esr-1
thunderbird	source	bullseye	1:128.13.0esr-1~deb11u1	DLA-4253-1
thunderbird	source	bookworm	1:128.13.0esr-1~deb12u1	DSA-5966-1
thunderbird	source	(unstable)	1:128.13.0esr-1

Notes

https://www.mozilla.org/en-US/security/advisories/mfsa2025-56/#CVE-2025-8027
https://www.mozilla.org/en-US/security/advisories/mfsa2025-58/#CVE-2025-8027
https://www.mozilla.org/en-US/security/advisories/mfsa2025-62/#CVE-2025-8027