CVE-2026-8090: Mozilla Firefox

High severity, CVSS 7.3. EPSS: 0.4% chance of exploitation in the next 30 days.

Use-after-free in the DOM: Networking component. This vulnerability was fixed in Firefox 150.0.2, Firefox ESR 140.10.2, Firefox ESR 115.35.2, Thunderbird 150.0.2, and Thunderbird 140.10.2.

Affected products

• Mozilla Firefox: before 115.35.2 (fixed in 115.35.2); before 150.0.2 (fixed in 150.0.2); from 128.0, before 140.10.2 (fixed in 140.10.2)
• Mozilla Thunderbird: before 140.10.2 (fixed in 140.10.2); before 150.0.2 (fixed in 150.0.2)

Published 2026-05-07. Last modified 2026-07-28.