What is CVE-2024-3862?

CVE-2024-3862 is a medium-severity vulnerability in Mozilla Firefox, classified under Use of Uninitialized Resource. CVSS score: 5.3/10. Published 2024-04-16.

How severe is CVE-2024-3862?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Vulnerability in Mozilla Firefox

CVE-2024-3862

The MarkStack assignment operator, part of the JavaScript engine, could access uninitialized memory if it were used in a self-assignment. This vulnerability affects Firefox < 125.

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

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N.

EPSS exploit prediction

EPSS: 0.004 (27.9th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 27.9% 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-908 — Use of Uninitialized Resource

References

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

Frequently asked questions

What is CVE-2024-3862?: CVE-2024-3862 is a medium-severity vulnerability in Mozilla Firefox, classified under Use of Uninitialized Resource. CVSS score: 5.3/10. Published 2024-04-16.
How severe is CVE-2024-3862?: Medium severity. CVSS v3 base score is 5.3 out of 10.