PT-2026-27400 · Mozilla · Firefox+1

Gary Kwong · Published 2026-03-24 · Updated 2026-03-24 · CVE-2026-4701

Mitre

Use-after-free in the JavaScript Engine component. This vulnerability affects Firefox < 149 and Firefox ESR < 140.9.

Related Identifiers

CVE-2026-4701

Affected Products

Firefox

Firefox Esr

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-4701 · Security Note
• https://mozilla.org/security/advisories/mfsa2026-20 · Vendor Advisory
• https://mozilla.org/security/advisories/mfsa2026-22 · Vendor Advisory
• https://bugzilla.mozilla.org/show_bug.cgi?id=2009303 · Note