CVE-2025-10534

Name: CVE-2025-10534
Creator: NVD / NIST
Published: 2025-09-16T13:15:48.007+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.1/10EPSS 0.33%

Last modified Jun 17, 2026

CVE-2025-10534 is a high-severity vulnerability rated 8.1/10 on the CVSS scale. Spoofing issue in the Site Permissions component. This vulnerability was fixed in Firefox 143 and Thunderbird 143.. EPSS estimates a 0.33% chance of exploitation in the next 30 days.

Description

Spoofing issue in the Site Permissions component. This vulnerability was fixed in Firefox 143 and Thunderbird 143.

Metrics

CVSS 3.1

8.1/10

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

EPSS Probability

0.33%

24.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-79

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 143.0
Mozilla	Thunderbird	< 143.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1665334Permissions 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-2025-10534?

Spoofing issue in the Site Permissions component. This vulnerability was fixed in Firefox 143 and Thunderbird 143.

How severe is CVE-2025-10534?

CVE-2025-10534 has a CVSS score of 8.1/10 (HIGH severity). The EPSS model estimates a 0.33% probability of exploitation in the next 30 days.

How do I fix CVE-2025-10534?

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-2025-10534?

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

Scan your code now

Source: NVD / NIST