CVE-2026-12289
HighCVSS 8.8Exploitation Probability (EPSS)
Low risk32th percentile - higher than 32% of all known CVEs
Summary
A privilege escalation vulnerability exists in the Graphics: WebRender component. It was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.
Risk Assessment
An attacker could exploit this vulnerability to gain elevated privileges, potentially leading to full control over the application or the underlying system.
Recommendation
Immediately update Firefox to version 152 or later, and ESR versions to 140.12/115.37. Update Thunderbird to version 152 or 140.12.
Other vulnerabilities in WebRender
See all- CVE-2026-2761Critical
A sandbox escape vulnerability exists in the Graphics: WebRender component of Firefox and Thunderbird. The flaw is fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.
- CVE-2026-2760Critical
A sandbox escape vulnerability exists in the WebRender component of Firefox and Thunderbird due to incorrect boundary conditions in graphics handling. The flaw is fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.
- CVE-2026-6750High
A privilege escalation vulnerability exists in the Graphics: WebRender component of Firefox and Thunderbird. It is fixed in Firefox 150, Firefox ESR 115.35, Firefox ESR 140.10, Thunderbird 150, and Thunderbird 140.10.
- CVE-2026-4684High
A race condition and use-after-free vulnerability was found in the WebRender component of Firefox and Thunderbird. It is fixed in Firefox 149, Firefox ESR 115.34, Firefox ESR 140.9, Thunderbird 149, and Thunderbird 140.9.
Original NVD description (English source)
Privilege escalation in the Graphics: WebRender component. This vulnerability was fixed in Firefox 152, Firefox ESR 140.12, Firefox ESR 115.37, Thunderbird 152, and Thunderbird 140.12.

