Mozilla Firefox up to 137 on Android Filename ui layer

Summaryinfo

A vulnerability classified as problematic has been found in Mozilla Firefox up to 137 on Android. The affected element is an unknown function of the component Filename Handler. Performing a manipulation results in ui layer. This vulnerability was named CVE-2025-4086. The attack may be initiated remotely. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Mozilla Firefox up to 137 on Android. This affects some unknown processing of the component Filename Handler. The manipulation with an unknown input leads to a ui layer vulnerability. CWE is classifying the issue as CWE-1021. The web application does not restrict or incorrectly restricts frame objects or UI layers that belong to another application or domain, which can lead to user confusion about which interface the user is interacting with. This is going to have an impact on integrity. The summary by CVE is:

A specially crafted filename containing a large number of encoded newline characters could obscure the file's extension when displayed in the download dialog. *This bug only affects Firefox for Android. Other versions of Firefox are unaffected.* This vulnerability affects Firefox < 138 and Thunderbird < 138.

It is possible to read the advisory at bugzilla.mozilla.org. This vulnerability is uniquely identified as CVE-2025-4086 since 04/29/2025. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. It demands that the victim is doing some kind of user interaction. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 01/30/2026).

The vulnerability scanner Nessus provides a plugin with the ID 297163 (Linux Distros Unpatched Vulnerability : CVE-2025-4086), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 138 eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (297163) and CERT Bund (WID-SEC-2025-1850). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Xerox FreeFlow Print Server

Productinfo

Type

• Web Browser

Vendor

• Mozilla

Name

• Firefox

Version

• 137

License

• open-source

Website

• Vendor: https://www.mozilla.org/
• Product: https://www.mozilla.org/en-US/firefox/

CPE 2.3info

• 🔍

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Entryinfo

Be aware that VulDB is the high quality source for vulnerability data.

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