CVE-2025-0238: Mozilla Firefox

Medium severity, CVSS 5.3. EPSS: 0.8% chance of exploitation in the next 30 days.

Assuming a controlled failed memory allocation, an attacker could have caused a use-after-free, leading to a potentially exploitable crash. This vulnerability was fixed in Firefox 134, Firefox ESR 128.6, Firefox ESR 115.19, Thunderbird 134, and Thunderbird 128.6.

Affected products

• Mozilla Firefox: before 115.19.0 (fixed in 115.19.0); before 134.0 (fixed in 134.0); from 116.0, before 128.6.0 (fixed in 128.6.0)
• Mozilla Thunderbird: before 128.6 (fixed in 128.6); from 129.0, before 134.0 (fixed in 134.0)

Published 2025-01-07. Last modified 2026-10-05.