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Medium · 5.3 CVE-2026-31808 EUVD-2026-10894GHSA-5v7r-6r5c-r473

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

Published Mar 10, 2026 · Updated Mar 11, 2026 · Assigned by GitHub_M

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.

Affected products

VendorProductAffectedFixed
sindresorhus file-type >= 13.0.0, < 21.3.1 —

Affected packages

EcosystemPackageAffectedFixedRecord
npm file-type >= 13.0.0, < 21.3.1 21.3.1 GHSA-5v7r-6r5c-r473

Advisories 2

References