CVE-2026-18446 (GCVE-0-2026-18446)
Vulnerability from cvelistv5
Published
2026-07-31 14:37
Modified
2026-07-31 17:47
Severity ?
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CWE
  • CWE-436 - Interpretation Conflict
Summary
fast-uri before 4.1.2, 3.1.5, and 2.4.4 requires a literal double forward slash to recognize a URI authority, so a reference that uses a backslash based introducer in place of it (backslash backslash, forward slash backslash, or backslash forward slash) is parsed with no authority and folds into the path. Node's native WHATWG URL parser instead treats a backslash as interchangeable with a forward slash for special schemes, so the two parsers extract different hosts from the same input. Applications that use fast-uri to enforce host based policy such as allowlists, SSRF filtering, or redirect validation before passing the same URL into Node's URL or fetch consumers can be steered to an unintended host. Upgrade to fast-uri 4.1.2, 3.1.5, or 2.4.4.
References
Impacted products
Vendor Product Version
fast-uri fast-uri Version: 4.0.0   ≤
Version: 3.0.0   ≤
Version: 0   ≤
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