Vulnerability · Published Apr 29, 2025 · Assigned by mozilla
CVE-2025-4086Specially crafted filename could be used to obscure download type
Medium 6.5
In plain English
A medium-severity security flaw in Firefox from Mozilla. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities).
Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.3%top 77.7% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Mozilla | Firefox | see references |
| Mozilla | Thunderbird | see references |
Weakness: CWE-451 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N