CVE-2023-6864

Name: CVE-2023-6864
Creator: NVD / NIST
Published: 2023-12-19T14:15:07.707+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.8/10EPSS 1.19%

Last modified Jun 17, 2026

CVE-2023-6864 is a high-severity vulnerability rated 8.8/10 on the CVSS scale. Memory safety bugs present in Firefox 120, Firefox ESR 115.5, and Thunderbird 115.5. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. EPSS estimates a 1.19% chance of exploitation in the next 30 days.

Description

Memory safety bugs present in Firefox 120, Firefox ESR 115.5, and Thunderbird 115.5. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox ESR < 115.6, Thunderbird < 115.6, and Firefox < 121.

Metrics

CVSS 3.1

8.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Probability

1.19%

64.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-787

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 121.0
Mozilla	Firefox Esr	< 115.6
Mozilla	Thunderbird	< 115.6
Debian	Debian Linux	10.0
Debian	Debian Linux	11.0
Debian	Debian Linux	12.0

References

https://bugzilla.mozilla.org/buglist.cgi?bug_id=1736385%2C1810805%2C1846328%2C1856090%2C1858033%2C1858509%2C1862089%2C1862777%2C1864015Broken Link, Issue Tracking
https://lists.debian.org/debian-lts-announce/2023/12/msg00020.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2023/12/msg00021.htmlMailing List, Third Party Advisory
https://security.gentoo.org/glsa/202401-10Third Party Advisory
https://www.debian.org/security/2023/dsa-5581Third Party Advisory
https://www.debian.org/security/2023/dsa-5582Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2023-54/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2023-55/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2023-56/Vendor Advisory
https://bugzilla.mozilla.org/buglist.cgi?bug_id=1736385%2C1810805%2C1846328%2C1856090%2C1858033%2C1858509%2C1862089%2C1862777%2C1864015Broken Link, Issue Tracking
https://lists.debian.org/debian-lts-announce/2023/12/msg00020.htmlMailing List, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2023/12/msg00021.htmlMailing List, Third Party Advisory
https://security.gentoo.org/glsa/202401-10Third Party Advisory
https://www.debian.org/security/2023/dsa-5581Third Party Advisory
https://www.debian.org/security/2023/dsa-5582Third Party Advisory
https://www.mozilla.org/security/advisories/mfsa2023-54/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2023-55/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2023-56/Vendor Advisory

Timeline

Published: Dec 19, 2023
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2023-6864?

How severe is CVE-2023-6864?

CVE-2023-6864 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 1.19% probability of exploitation in the next 30 days.

How do I fix CVE-2023-6864?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2023-6864?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST