CVE-2025-4086mediumCWE-451

CVE-2025-4086: medium-severity vulnerability in Mozilla Thunderbird

Specially crafted filename could be used to obscure download type

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13Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 6.5epss 0.3%
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
Affected products
Mozilla · FirefoxMozilla · Thunderbird
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