CVE-2026-2796

JIT miscompilation in the JavaScript: WebAssembly component

JIT miscompilation in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 148 and Thunderbird 148.

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

0.67% chance of exploitation in the next 30 days, 51st percentile

Published

2026-02-24

Updated

2026-07-15

Proof-of-concept exploits (3)

• WostGit/CVE-2026-27960★ · 2026-04-09
• WostGit/cve-2026-2796-repro0★ · 2026-04-09
• SneakyNachos/CVE-2026-2796-escape-wasm-by-using-wasm/blob/2c5ccf96b465e3d7930a58c2ad9535a…5★ · 2026-08-20

Security advisories

• https://www.mozilla.org/security/advisories/mfsa2026-13
• https://www.mozilla.org/security/advisories/mfsa2026-16

References

• CVE Record
• NVD entry

Related

• CVE-2024-29943
• CVE-2026-12295
• CVE-2026-15718
• CVE-2026-2764
• CVE-2026-2766
• CVE-2026-4692