CVE-2026-12299

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 JIT miscompilation occurs in the DOM: Core & HTML component. JIT (Just-In-Time) compilation is a method used by software to improve execution speed by compiling code during runtime.

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.