CVE-2025-8031: firefox Permission Flaw — Fix

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.

Is your site exposed to CVE-2025-8031?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

9.8

CRITICAL

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

Weakness Type (CWE)

CWE-276 Incorrect Default Permissions

Affected Products

Vendor	Product	Versions
mozilla	firefox	< 128.13.0
mozilla	firefox	< 141.0
mozilla	firefox	140.0 — 140.1.0
mozilla	thunderbird	< 128.13.0
mozilla	thunderbird	< 141.0
mozilla	thunderbird	140.0 — 140.1.0

References

Advisories & Patches

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/

Other References

https://bugzilla.mozilla.org/show_bug.cgi?id=1971719 https://lists.debian.org/debian-lts-announce/2025/07/msg00016.html

Frequently Asked Questions

What is CVE-2025-8031? +

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. It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2025-8031? +

CVE-2025-8031 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately.

What products are affected by CVE-2025-8031? +

CVE-2025-8031 affects products from mozilla, specifically: firefox, thunderbird. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-8031? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-20718

Incorrect default permissions for some Intel(R) NPU Driver software installers before version 32.0.100.4511 within Ring 3: User Applications may allow …

CVE-2026-0539

Incorrect Default Permissions in pcvisit service binary on Windows allows a low-privileged local attacker to escalate their privileges by overwriting …

CVE-2025-2782

The WatchGuard Terminal Services Agent on Windows does not properly configure directory permissions when installed in a non-default directory. This …

CVE-2025-2781

The WatchGuard Mobile VPN with SSL Client on Windows does not properly configure directory permissions when installed in a non-default …

CVE-2025-4280

MacOS version of Poedit bundles a Python interpreter that inherits the Transparency, Consent, and Control (TCC) permissions granted by the …

CVE-2025-4412

On macOS systems, by utilizing a Launch Agent and loading the viscosity_openvpn process from the application bundle, it is possible …

CVE-2025-8031