Vulnerability in Mozilla Firefox

CVE-2026-2796

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

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.007 (49.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 49.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-2796: held from 0.006 to 0.007.

EPSS over last 30 days · oldest: 0.006 · newest: 0.007 · change: +0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2026-2796?
CVE-2026-2796 is a critical-severity vulnerability in Mozilla Firefox, classified under Access of Resource Using Incompatible Type (Type Confusion). CVSS score: 9.8/10. Published 2026-02-24.
How severe is CVE-2026-2796?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2026-2796 known to be exploited?
4 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.