CVE-2025-55031

Name: CVE-2025-55031
Creator: NVD / NIST
Published: 2025-08-19T21:15:28.34+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 0.39%

Last modified Jun 17, 2026

CVE-2025-55031 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. 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 computer into the target account. EPSS estimates a 0.39% chance of exploitation in the next 30 days.

Description

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 computer into the target account. This vulnerability was fixed in Firefox for iOS 142 and Focus for iOS 142.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

0.39%

30.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-601

Affected Software

Vendor	Product	Versions
Mozilla	Firefox	< 142.0
Mozilla	Firefox Focus	< 142.0

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1979499Issue Tracking, Permissions Required
https://bugzilla.mozilla.org/show_bug.cgi?id=1979804Issue Tracking, Permissions Required
https://www.mozilla.org/security/advisories/mfsa2025-68/Vendor Advisory
https://www.mozilla.org/security/advisories/mfsa2025-69/Vendor Advisory

Timeline

Published: Aug 19, 2025
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2025-55031?

How severe is CVE-2025-55031?

CVE-2025-55031 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.39% probability of exploitation in the next 30 days.

How do I fix CVE-2025-55031?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-55031?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST