What is CVE-2026-2801?

CVE-2026-2801 is a high-severity vulnerability in Mozilla Firefox, classified under Improper Check for Unusual or Exceptional Conditions. CVSS score: 7.5/10. Published 2026-02-24.

How severe is CVE-2026-2801?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Mozilla Firefox

CVE-2026-2801

Incorrect boundary conditions in the JavaScript: WebAssembly component. This vulnerability was fixed in Firefox 148 and Thunderbird 148.

EPSS: 0.003 (21.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Mozilla Firefox — versions 148
Mozilla Thunderbird — versions 148

Weakness classification (CWE)

CWE-754 — Improper Check for Unusual or Exceptional Conditions

References

security@mozilla.org (Permissions Required)
security@mozilla.org (Vendor Advisory)
security@mozilla.org (Vendor Advisory)

Frequently asked questions

What is CVE-2026-2801?: CVE-2026-2801 is a high-severity vulnerability in Mozilla Firefox, classified under Improper Check for Unusual or Exceptional Conditions. CVSS score: 7.5/10. Published 2026-02-24.
How severe is CVE-2026-2801?: High severity. CVSS v3 base score is 7.5 out of 10.