What’s Vulnerable › Vulnerabilities

CVE-2025-8031: Incorrect URL stripping in CSP reports

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% 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-276

Description

The `username:password` part was not correctly stripped from URLs in CSP reports potentially leaking HTTP Basic Authentication credentials. This vulnerability was fixed in Firefox 141, Firefox ESR 128.13, Firefox ESR 140.1, Thunderbird 141, Thunderbird 128.13, and Thunderbird 140.1.

Affected products

• Mozilla Firefox: before 128.13.0; before 141.0; from 140.0 before 140.1.0 — fixed in 128.13.0, 140.1.0, 141.0
• Mozilla Thunderbird: before 128.13.0; before 141.0; from 140.0 before 140.1.0 — fixed in 128.13.0, 140.1.0, 141.0

How to fix

Upgrade to a fixed version: Mozilla Firefox 128.13.0, 140.1.0, 141.0; Mozilla Thunderbird 128.13.0, 140.1.0, 141.0. Check the vendor advisory for mitigations.

References

• https://bugzilla.mozilla.org/show_bug.cgi?id=1971719
• https://www.mozilla.org/security/advisories/mfsa2025-56/
• https://www.mozilla.org/security/advisories/mfsa2025-58/
• https://www.mozilla.org/security/advisories/mfsa2025-59/
• https://www.mozilla.org/security/advisories/mfsa2025-61/
• https://www.mozilla.org/security/advisories/mfsa2025-62/
• https://www.mozilla.org/security/advisories/mfsa2025-63/
• https://lists.debian.org/debian-lts-announce/2025/07/msg00016.html

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