CVE-2026-117883

Name of the Vulnerable Software and Affected Versions Firefox versions prior to 159 Firefox ESR versions prior to 115.44 Firefox ESR versions prior to 153.6 Thunderbird versions prior to 159 Thunderbird versions prior to 153.6

Description A use-after-free issue exists in the DOM: HTML Parser component. Use-after-free is a memory corruption flaw that occurs when an application continues to use a pointer after it has been freed.

Recommendations Update Firefox to version 159. Update Firefox ESR to version 115.44. Update Firefox ESR to version 153.6. Update Thunderbird to version 159. Update Thunderbird to version 153.6.