CVE-2026-31808

CVE-2026-31808 · file-type affected by infinite loop in ASF parser on malformed input with zero-size sub-header

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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 5.3 · Medium · EPSS 0.3% · Fix available

Published

2026-03-10T21:01:55.466Z

Updated

2026-03-11T16:00:14.754Z

Stack: node

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