CVE-2025-10531

Name: CVE-2025-10531
Creator: NVD / NIST
Published: 2025-09-16T13:15:46.617+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.4/10EPSS 0.26%

Last modified Jun 17, 2026

CVE-2025-10531 is a medium-severity vulnerability rated 5.4/10 on the CVSS scale. Mitigation bypass in the Web Compatibility: Tooling component. This vulnerability was fixed in Firefox 143 and Thunderbird 143.. EPSS estimates a 0.26% chance of exploitation in the next 30 days.

Description

Mitigation bypass in the Web Compatibility: Tooling component. This vulnerability was fixed in Firefox 143 and Thunderbird 143.

Metrics

CVSS 3.1

5.4/10

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

EPSS Probability

0.26%

16.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-288

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 143.0
Mozilla	Thunderbird	< 143.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1978453Permissions Required
https://www.mozilla.org/security/advisories/mfsa2025-73/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-77/Vendor Advisory

Timeline

Published: Sep 16, 2025
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2025-10531?

Mitigation bypass in the Web Compatibility: Tooling component. This vulnerability was fixed in Firefox 143 and Thunderbird 143.

How severe is CVE-2025-10531?

CVE-2025-10531 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 0.26% probability of exploitation in the next 30 days.

How do I fix CVE-2025-10531?

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-2025-10531?

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

Scan your code now

Source: NVD / NIST