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.
Conclusion & alert: CVE-2025-8031 is rated Moderate Risk (61.7/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 0.44%). Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-05-18 | 0.12% | 0.44% | +0.33% |
| 2 | 2026-02-25 | 0.16% | 0.12% | -0.04% |
| 3 | 2026-02-15 | — | 0.16% | — |
Full EPSS history (7 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 9.8 | 3.1 | CRITICAL |
|
3.9 | 5.9 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
| vendor | priority | summary | link |
|---|---|---|---|
alpine
|
— | CVE-2025-8031: 3 source package rows (firefox, firefox-esr, thunderbird); 381 state rows across 2 repos (3.22-community, edge-community); fixed 0, open 381. | https://security.alpinelinux.org/vuln/CVE-2025-8031 |
debian
|
not yet assigned | CVE-2025-8031 not yet assigned priority: Debian including 3 source packages (firefox, firefox-esr, thunderbird), 11 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 11. | https://security-tracker.debian.org/tracker/CVE-2025-8031 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2025-8031 |
suse
|
high | CVE-2025-8031 severity important: SUSE including 79 source package names (2.1.3-4.11:qemu-guest-agent-8.2.7-1.1, MozillaFirefox-140.1.0-112.273.1, …), 356 product×package rows across 47 product lines (Container suse/sl-micro/6.0/kvm-os-container, Image SLES12-SP5-SAP-Azure-LI-BYOS-Production, … (47 product lines)): Fixed 353, First Fixed 3. | https://www.suse.com/security/cve/CVE-2025-8031/ |
ubuntu
|
medium | CVE-2025-8031 medium priority: Ubuntu including 9 source packages (firefox, mozjs102, …), 49 status rows across 7 suites (bionic, focal, jammy, noble, plucky, questing, upstream): DNE 22, ignored 9, needs-triage 9, not-affected 7, released 2. | https://ubuntu.com/security/CVE-2025-8031 |
| Vendor | Product | Version | Raw CPE |
|---|---|---|---|
| mozilla | firefox | < 128.13.0 | cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* |
| mozilla | firefox | < 141.0 | cpe:2.3:a:mozilla:firefox:*:*:*:*:-:*:*:* |
| mozilla | firefox | >= 140.0, < 140.1.0 | cpe:2.3:a:mozilla:firefox:*:*:*:*:esr:*:*:* |
| mozilla | thunderbird | < 128.13.0 | cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:* |
| mozilla | thunderbird | < 141.0 | cpe:2.3:a:mozilla:thunderbird:*:*:*:*:-:*:*:* |
| mozilla | thunderbird | >= 140.0, < 140.1.0 | cpe:2.3:a:mozilla:thunderbird:*:*:*:*:esr:*:*:* |
| URL | Tags |
|---|---|
| https://bugzilla.mozilla.org/show_bug.cgi?id=1971719 | Permissions Required |
| https://www.mozilla.org/security/advisories/mfsa2025-56/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2025-58/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2025-59/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2025-61/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2025-62/ | Vendor Advisory |
| https://www.mozilla.org/security/advisories/mfsa2025-63/ | Vendor Advisory |
| https://lists.debian.org/debian-lts-announce/2025/07/msg00016.html |