What is CVE-2025-8043?

CVE-2025-8043 is a critical-severity vulnerability in Mozilla Firefox, classified under User Interface (UI) Misrepresentation of Critical Information. CVSS score: 9.8/10. Published 2025-07-22.

How severe is CVE-2025-8043?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Vulnerability in Mozilla Firefox

CVE-2025-8043

Focus incorrectly truncated URLs towards the beginning instead of around the origin. This vulnerability was fixed in Firefox 141.

Published 2025-07-22 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.004 (29.5th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 29th percentile — 29.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Mozilla Firefox — versions 141
Mozilla Thunderbird

Weakness classification (CWE)

CWE-451 — User Interface (UI) Misrepresentation of Critical Information

References

bugzilla.mozilla.org/show_bug.cgi (Exploit, Issue Tracking)
www.mozilla.org/security/advisories/mfsa2025-56/ (Vendor Advisory)

Frequently asked questions

What is CVE-2025-8043?: CVE-2025-8043 is a critical-severity vulnerability in Mozilla Firefox, classified under User Interface (UI) Misrepresentation of Critical Information. CVSS score: 9.8/10. Published 2025-07-22.
How severe is CVE-2025-8043?: Critical severity. CVSS v3 base score is 9.8 out of 10.