CVE-2026-2764

JIT miscompilation, use-after-free in the JavaScript Engine: JIT component

JIT miscompilation, use-after-free in the JavaScript Engine: JIT component. This vulnerability was fixed in Firefox 148, Firefox ESR 115.33, Firefox ESR 140.8, Thunderbird 148, and Thunderbird 140.8.

Affected

Mozilla · Firefox · Thunderbird

CVSS v3.1 NVD

9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 CNA

7.5 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS

0.61% chance of exploitation in the next 30 days, 48th percentile

Published

2026-02-24

Updated

2026-07-15

Proof-of-concept exploits (1)

• SneakyNachos/CVE-2026-2764-but-with-wasm1★ · 2026-08-11

Security advisories

• https://www.mozilla.org/security/advisories/mfsa2026-13
• https://www.mozilla.org/security/advisories/mfsa2026-14
• https://www.mozilla.org/security/advisories/mfsa2026-15
• https://www.mozilla.org/security/advisories/mfsa2026-16
• https://www.mozilla.org/security/advisories/mfsa2026-17
• https://bugzilla.mozilla.org/show_bug.cgi?id=2012608

References

• CVE Record
• NVD entry

Related

• CVE-2024-29943
• CVE-2026-12295
• CVE-2026-15718
• CVE-2026-2766
• CVE-2026-2796
• CVE-2026-4692