Improper Validation of Specified Quantity in Input Affecting fast-uri package, versions >=2.4.2 <2.4.8>=3.1.3 <3.1.9>=4.0.1 <4.2.3
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JS-FASTURI-21279304
- published20 Oct 2026
- disclosed20 Oct 2026
- creditzekth
Introduced: 20 Oct 2026
NewCVE-2026-110180 (opens in a new tab)How to fix?
Upgrade fast-uri to version 2.4.8, 3.1.9, 4.2.3 or higher.
Overview
fast-uri is a Dependency-free RFC 3986 URI toolbox
Affected versions of this package are vulnerable to Improper Validation of Specified Quantity in Input via canonicalizeHost(), which passes the host directly to new URL('http://' + host) without verifying that the WHATWG parser consumed the entire input as a host. Because the RFC 3986 parser permits @ in the host component, and the WHATWG parser silently strips TAB, LF, and CR, an attacker can supply a URI whose authority is rewritten by the second parser with no error. This allows host spoofing across parse(), normalize(), equal(), and resolve() - for example, parse('http://a@b@evil.com/').host returns 'evil.com' and normalize('http://ev\til.com/p') returns 'http://evil.com/p'.