CSRF in Mozilla Firefox

CVE-2025-4088

A security vulnerability in Thunderbird allowed malicious sites to use redirects to send credentialed requests to arbitrary endpoints on any site that had invoked the Storage Access API. This enabled potential Cross-Site Request Forgery attacks across origins. This vulnerability was fixed in Firefox 138 and Thunderbird 138.

Vulnerability class: CSRF (Cross-Site Request Forgery)

EPSS: 0.002 (5.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-4088?
CVE-2025-4088 is a medium-severity vulnerability in Mozilla Firefox, classified under Cross-Site Request Forgery (CSRF). CVSS score: 6.5/10. Published 2025-04-29.
How severe is CVE-2025-4088?
Medium severity. CVSS v3 base score is 6.5 out of 10.