CVE-2026-109776

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 158 Firefox ESR versions prior to 153.5 Thunderbird versions prior to 158 Thunderbird versions prior to 153.5

Description A race condition exists in the XPCOM component. A race condition is a situation where the system's substantive behavior is dependent on the sequence or timing of other uncontrollable events.

Recommendations Update Firefox to version 158. Update Firefox ESR to version 153.5. Update Thunderbird to version 158. Update Thunderbird to version 153.5.