Vulnerability Description
file-type detects the file type of a file, stream, or data. Prior to 21.3.1, a denial of service vulnerability exists in the ASF (WMV/WMA) file type detection parser. When parsing a crafted input where an ASF sub-header has a size field of zero, the parser enters an infinite loop. The payload value becomes negative (-24), causing tokenizer.ignore(payload) to move the read position backwards, so the same sub-header is read repeatedly forever. Any application that uses file-type to detect the type of untrusted/attacker-controlled input is affected. An attacker can stall the Node.js event loop with a 55-byte payload. Fixed in version 21.3.1.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Sindresorhus | File-Type | >= 13.0.0, < 21.3.1 |
Related Weaknesses (CWE)
References
- https://github.com/sindresorhus/file-type/commit/319abf871b50ba2fa221b4a7050059fPatch
- https://github.com/sindresorhus/file-type/security/advisories/GHSA-5v7r-6r5c-r47MitigationPatchVendor Advisory
FAQ
What is CVE-2026-31808?
CVE-2026-31808 is a vulnerability with a CVSS score of 5.3 (MEDIUM). file-type detects the file type of a file, stream, or data. Prior to 21.3.1, a denial of service vulnerability exists in the ASF (WMV/WMA) file type detection parser. When parsing a crafted input wher...
How severe is CVE-2026-31808?
CVE-2026-31808 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-31808?
Check the references section above for vendor advisories and patch information. Affected products include: Sindresorhus File-Type.