Mozilla · Firefox · CVE-2026-74946
**Name of the Vulnerable Software and Affected Versions**
Firefox versions prior to 154
Firefox ESR versions prior to 115.39
Firefox ESR versions prior to 140.14
Firefox ESR versions prior to 153.1
Thunderbird versions prior to 154
Thunderbird versions prior to 140.14
Thunderbird versions prior to 153.1
**Description**
Privilege escalation is possible due to incorrect boundary conditions within the Graphics: CanvasWebGL component.
**Recommendations**
Update Firefox to version 154.
Update Firefox ESR to version 115.39.
Update Firefox ESR to version 140.14.
Update Firefox ESR to version 153.1.
Update Thunderbird to version 154.
Update Thunderbird to version 140.14.
Update Thunderbird to version 153.1.