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.
History

Tue, 10 Mar 2026 21:15:00 +0000

Type Values Removed Values Added
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.
Title file-type affected by infinite loop in ASF parser on malformed input with zero-size sub-header
Weaknesses CWE-835
References
Metrics cvssV3_1

{'score': 5.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-03-10T21:01:55.466Z

Reserved: 2026-03-09T16:33:42.913Z

Link: CVE-2026-31808

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-03-10T21:16:50.173

Modified: 2026-03-10T21:16:50.173

Link: CVE-2026-31808

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.