CVE-2025-2857

Name	CVE-2025-2857
Description	Following the recent Chrome sandbox escape (CVE-2025-2783), various Firefox developers identified a similar pattern in our IPC code. A compromised child process could cause the parent process to return an unintentionally powerful handle, leading to a sandbox escape. The original vulnerability was being exploited in the wild. This only affects Firefox on Windows. Other operating systems are unaffected. This vulnerability affects Firefox < 136.0.4, Firefox ESR < 128.8.1, and Firefox ESR < 115.21.1.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, 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
firefox (PTS)	sid	137.0-1	fixed
firefox-esr (PTS)	bullseye	115.14.0esr-1~deb11u1	fixed
	bullseye (security)	128.9.0esr-1~deb11u1	fixed
	bookworm	128.8.0esr-1~deb12u1	fixed
	bookworm (security)	128.9.0esr-1~deb12u1	fixed
	trixie	128.8.0esr-1	fixed
	sid	128.9.0esr-2	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
firefox	source	(unstable)	(not affected)
firefox-esr	source	(unstable)	(not affected)

Notes

- firefox <not-affected> (Only affects Firefox on Windows)
- firefox-esr <not-affected> (Only affects Firefox ESR on Windows)
https://www.mozilla.org/en-US/security/advisories/mfsa2025-19/#CVE-2025-2857