CVE-2023-4049

Severity: medium (CVSS 5.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.6% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2023-08-01 · updated 2026-10-23
Weakness: CWE-362

Description

Race conditions in reference counting code were found through code inspection. These could have resulted in potentially exploitable use-after-free vulnerabilities. This vulnerability affects Firefox < 116, Firefox ESR < 102.14, and Firefox ESR < 115.1.

Affected products

Debian Linux: 11.0, 12.0
Mozilla Firefox: before 116.0; from 102.0 before 102.14; from 115.0 before 115.1 — fixed in 102.14, 115.1, 116.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 102.14, 115.1, 116.0. Check the vendor advisory for mitigations.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1842658
https://lists.debian.org/debian-lts-announce/2023/08/msg00008.html
https://lists.debian.org/debian-lts-announce/2023/08/msg00010.html
https://www.debian.org/security/2023/dsa-5464
https://www.debian.org/security/2023/dsa-5469
https://www.mozilla.org/security/advisories/mfsa2023-29/
https://www.mozilla.org/security/advisories/mfsa2023-30/
https://www.mozilla.org/security/advisories/mfsa2023-31/
https://bugzilla.mozilla.org/show_bug.cgi?id=1842658
https://lists.debian.org/debian-lts-announce/2023/08/msg00008.html
https://lists.debian.org/debian-lts-announce/2023/08/msg00010.html
https://www.debian.org/security/2023/dsa-5464

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