Open Redirect in Mozilla Firefox

CVE-2025-55031

Malicious pages could use Firefox for iOS to pass FIDO: links to the OS and trigger the hybrid passkey transport. An attacker within Bluetooth range could have used this to trick the user into using their passkey to log the attacker's comp…

Vulnerability class: Open Redirect

EPSS: 0.004 (33.7th percentile) — read the EPSS interpretation.

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.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-55031?
CVE-2025-55031 is a critical-severity vulnerability in Mozilla Firefox, classified under URL Redirection to Untrusted Site (Open Redirect). CVSS score: 9.8/10. Published 2025-08-19.
How severe is CVE-2025-55031?
Critical severity. CVSS v3 base score is 9.8 out of 10.