CVE-2026-9903

Name	CVE-2026-9903
Description	Insufficient validation of untrusted input in Site Isolation in Google Chrome prior to 148.0.7778.216 allowed a remote attacker who had compromised the renderer process to bypass site isolation via a crafted MHTML page. (Chromium security severity: High)
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
chromium (PTS)	bullseye (security), bullseye	120.0.6099.224-1~deb11u1	vulnerable
	bookworm	147.0.7727.137-1~deb12u1	vulnerable
	bookworm (security)	148.0.7778.178-1~deb12u1	vulnerable
	trixie	147.0.7727.137-1~deb13u1	vulnerable
	trixie (security)	148.0.7778.178-1~deb13u1	vulnerable
	forky, sid	148.0.7778.178-1	vulnerable

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

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

[bullseye] - chromium <end-of-life> (see #1061268)