What is CVE-2024-3853?

CVE-2024-3853 is a high-severity vulnerability in Mozilla Firefox, classified under Use After Free. CVSS score: 7.5/10. Published 2024-04-16.

How severe is CVE-2024-3853?

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

Use After Free in Mozilla Firefox

CVE-2024-3853

A use-after-free could result if a JavaScript realm was in the process of being initialized when a garbage collection started. This vulnerability affects Firefox < 125.

Vulnerability class: Use-After-Free

Published 2024-04-16 · last modified 2026-06-17.

CVSS v3 metric

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

EPSS exploit prediction

EPSS: 0.004 (27.0th percentile), scored 2026-10-04.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 27.0% 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-416 — Use After Free

References

bugzilla.mozilla.org/show_bug.cgi (Issue Tracking)
www.mozilla.org/security/advisories/mfsa2024-18/ (Vendor Advisory)

Frequently asked questions

What is CVE-2024-3853?: CVE-2024-3853 is a high-severity vulnerability in Mozilla Firefox, classified under Use After Free. CVSS score: 7.5/10. Published 2024-04-16.
How severe is CVE-2024-3853?: High severity. CVSS v3 base score is 7.5 out of 10.