CVE-2025-4083

Name	CVE-2025-4083
Description	A process isolation vulnerability in Thunderbird stemmed from improper handling of javascript: URIs, which could allow content to execute in the top-level document's process instead of the intended frame, potentially enabling a sandbox escape. This vulnerability affects Firefox < 138, Firefox ESR < 128.10, Firefox ESR < 115.23, Thunderbird < 138, and Thunderbird < 128.10.
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-4167-1, DLA-4172-1, DSA-5910-1, DSA-5912-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
firefox (PTS)	sid	138.0.4-1	fixed
firefox-esr (PTS)	bullseye	115.14.0esr-1~deb11u1	vulnerable
	bullseye (security)	128.10.1esr-1~deb11u1	fixed
	bookworm	128.10.0esr-1~deb12u1	fixed
	bookworm (security)	128.10.1esr-1~deb12u1	fixed
	trixie, sid	128.10.1esr-1	fixed
thunderbird (PTS)	bullseye	1:115.12.0-1~deb11u1	vulnerable
	bullseye (security)	1:128.10.1esr-1~deb11u1	fixed
	bookworm	1:128.10.0esr-1~deb12u1	fixed
	bookworm (security)	1:128.10.1esr-1~deb12u1	fixed
	trixie	1:128.10.0esr-1	fixed
	sid	1:128.10.1esr-1	fixed

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

Package	Type	Release	Fixed Version	Origin
firefox	source	(unstable)	138.0-1
firefox-esr	source	bullseye	128.10.1esr-1~deb11u1	DLA-4172-1
firefox-esr	source	bookworm	128.10.0esr-1~deb12u1	DSA-5910-1
firefox-esr	source	(unstable)	128.10.0esr-1
thunderbird	source	bullseye	1:128.10.1esr-1~deb11u1	DLA-4167-1
thunderbird	source	bookworm	1:128.10.0esr-1~deb12u1	DSA-5912-1
thunderbird	source	(unstable)	1:128.10.0esr-1

Notes

https://www.mozilla.org/en-US/security/advisories/mfsa2025-28/#CVE-2025-4083
https://www.mozilla.org/en-US/security/advisories/mfsa2025-29/#CVE-2025-4083
https://www.mozilla.org/en-US/security/advisories/mfsa2025-32/#CVE-2025-4083