CVE-2025-1934: Mozilla Firefox

Medium severity, CVSS 6.5. EPSS: 0.5% chance of exploitation in the next 30 days.

It was possible to interrupt the processing of a RegExp bailout and run additional JavaScript, potentially triggering garbage collection when the engine was not expecting it. This vulnerability was fixed in Firefox 136, Firefox ESR 128.8, Thunderbird 136, and Thunderbird 128.8.

Affected products

• Mozilla Firefox: before 128.8.0 (fixed in 128.8.0); before 136.0 (fixed in 136.0)
• Mozilla Thunderbird: before 128.8.0 (fixed in 128.8.0); from 129.0, before 136.0 (fixed in 136.0)

Published 2025-03-04. Last modified 2026-10-05.