What is CVE-2024-4776?

CVE-2024-4776 is a high-severity vulnerability in Mozilla Firefox, classified under Cross-site Scripting. CVSS score: 8.2/10. Published 2024-05-14.

How severe is CVE-2024-4776?

High severity. CVSS v3 base score is 8.2 out of 10.

XSS in Mozilla Firefox

CVE-2024-4776

A file dialog shown while in full-screen mode could have resulted in the window remaining disabled. This vulnerability affects Firefox < 126.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2024-05-14 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:H.

EPSS exploit prediction

EPSS: 0.004 (33.8th percentile), scored 2026-10-06.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 34th percentile — 33.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Mozilla Firefox — versions unspecified

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

bugzilla.mozilla.org/show_bug.cgi (Exploit, Issue Tracking, Vendor Advisory)
www.mozilla.org/security/advisories/mfsa2024-21/ (Vendor Advisory)

Frequently asked questions

What is CVE-2024-4776?: CVE-2024-4776 is a high-severity vulnerability in Mozilla Firefox, classified under Cross-site Scripting. CVSS score: 8.2/10. Published 2024-05-14.
How severe is CVE-2024-4776?: High severity. CVSS v3 base score is 8.2 out of 10.