What is CVE-2023-29551?

CVE-2023-29551 is a high-severity vulnerability in Mozilla Firefox, classified under Out-of-bounds Write. CVSS score: 8.8/10. Published 2023-06-02.

How severe is CVE-2023-29551?

High severity. CVSS v3 base score is 8.8 out of 10.

Buffer overflow in Mozilla Firefox

CVE-2023-29551

Memory safety bugs present in Firefox 111. 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 for Android < 112, Firefox < 112, and Focus for Android < 112.

Vulnerability class: Buffer Overflow

Published 2023-06-02 · last modified 2026-08-19.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.005 (42.0th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 42nd percentile — 42.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000

Affected products

Mozilla Firefox — versions unspecified
Mozilla Firefox For Android — versions unspecified
Mozilla Firefox Mobile
Mozilla Focus
Mozilla Focus For Android — versions unspecified

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

www.mozilla.org/security/advisories/mfsa2023-13/ (Vendor Advisory)
bugzilla.mozilla.org/buglist.cgi (Issue Tracking, Not Applicable)

Frequently asked questions

What is CVE-2023-29551?: CVE-2023-29551 is a high-severity vulnerability in Mozilla Firefox, classified under Out-of-bounds Write. CVSS score: 8.8/10. Published 2023-06-02.
How severe is CVE-2023-29551?: High severity. CVSS v3 base score is 8.8 out of 10.