CVE-2026-12294

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 152 Firefox ESR versions prior to 140.12 Firefox ESR versions prior to 115.37 Thunderbird versions prior to 152 Thunderbird versions prior to 140.12

Description A sandbox escape exists within the DOM: Workers component. A sandbox is a security mechanism for separating running programs, usually in an effort to mitigate system failures or software vulnerabilities from spreading.

Recommendations Update Firefox to version 152. Update Firefox ESR to version 140.12. Update Firefox ESR to version 115.37. Update Thunderbird to version 152. Update Thunderbird to version 140.12.