CVE-2026-0884

Use-after-free in the JavaScript Engine component. This vulnerability affects Firefox < 147, Firefox ESR < 140.7, Thunderbird < 147, and Thunderbird < 140.7.

• https://bugzilla.mozilla.org/show_bug.cgi?id=2003588
• https://www.mozilla.org/security/advisories/mfsa2026-01/
• https://www.mozilla.org/security/advisories/mfsa2026-03/
• https://www.mozilla.org/security/advisories/mfsa2026-04/
• https://www.mozilla.org/security/advisories/mfsa2026-05/