What is CVE-2025-13027?

CVE-2025-13027 is a high-severity vulnerability in Mozilla Firefox, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 8.1/10. Published 2025-11-11.

How severe is CVE-2025-13027?

High severity. CVSS v3 base score is 8.1 out of 10.

Buffer overflow in Mozilla Firefox

CVE-2025-13027

Memory safety bugs present in Firefox 144 and Thunderbird 144. 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…

Vulnerability class: Buffer Overflow

EPSS: 0.003 (21.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Mozilla Firefox — versions 145
Mozilla Thunderbird — versions 145

Weakness classification (CWE)

CWE-119 — Improper Restriction of Operations within the Bounds of a Memory Buffer

References

Frequently asked questions

What is CVE-2025-13027?: CVE-2025-13027 is a high-severity vulnerability in Mozilla Firefox, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 8.1/10. Published 2025-11-11.
How severe is CVE-2025-13027?: High severity. CVSS v3 base score is 8.1 out of 10.