Improper isolation or compartmentalization in Mozilla products - CVE-2026-124927
Published: November 10, 2026
Vulnerability identifier: #VU164554
CSH Severity: Medium
CVSS v4: 5.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-124927
CWE-ID: CWE-653
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to weaken site isolation, potentially accessing resources across site boundaries.
The vulnerability exists due to insufficient site isolation enforcement in the Graphics: WebRender component when rendering content. A remote attacker can trigger affected rendering behavior to cross intended site boundaries and potentially access otherwise isolated resources.
Affected software
Firefox ESR
Mozilla Firefox
Firefox for Android
Mozilla Firefox
Firefox for Android
How to mitigate CVE-2026-124927
Install security update from vendor's website.
Firefox ESR - update to 153.7.0
Firefox for Android - update to 160.0
Mozilla Firefox - update to 160.0
Firefox for Android - update to 160.0
Mozilla Firefox - update to 160.0