CVE-2025-55031 Affecting firefox package, versions <142-r0
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-CHAINGUARDLATEST-FIREFOX-17764343
- published1 Jul 2026
- disclosed19 Aug 2025
Introduced: 19 Aug 2025
CVE-2025-55031 (opens in a new tab)How to fix?
Upgrade Chainguard firefox to version 142-r0 or higher.
NVD Description
Note: Versions mentioned in the description apply only to the upstream firefox package and not the firefox package as distributed by Chainguard.
See How to fix? for Chainguard relevant fixed versions and status.
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.