CVE-2025-8038: CSP frame-src was not correctly enforced for paths

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-07-22 · updated 2026-10-05
Weakness: CWE-345

Description

Thunderbird ignored paths when checking the validity of navigations in a frame. This vulnerability was fixed in Firefox 141, Firefox ESR 140.1, Thunderbird 141, and Thunderbird 140.1.

Affected products

Mozilla Firefox: before 140.1.0; before 141.0 — fixed in 140.1.0, 141.0
Mozilla Thunderbird: before 140.1.0; before 141.0 — fixed in 140.1.0, 141.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 140.1.0, 141.0; Mozilla Thunderbird 140.1.0, 141.0. Check the vendor advisory for mitigations.

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1808979
https://www.mozilla.org/security/advisories/mfsa2025-56/
https://www.mozilla.org/security/advisories/mfsa2025-59/
https://www.mozilla.org/security/advisories/mfsa2025-61/
https://www.mozilla.org/security/advisories/mfsa2025-63/

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