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CVE-2025-4086

Medium

Description

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 Thunderbird for Android. Other versions of Thunderbird are unaffected.*. This vulnerability was fixed in Firefox 138 and Thunderbird 138.

SeverityMedium
CVSS6.5
Exploit probability—
ProductMozilla Firefox
PublishedApr 29, 2025
First seenApr 29, 2025
Weakness typeCWE-451CWE-451

How to fix

Update
  • mozilla firefox138.0 or later
  • mozilla thunderbird138.0 or later

Affected products

ProductAffected versionsFixed in
mozilla firefoxv < 138.0138.0
mozilla thunderbirdv < 138.0138.0

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