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CVE PROGRAM SOURCE RECORD7.5 High

CVE-2026-84292

fast-uri vulnerable to authority injection via an unvalidated port in serialize

Description

fast-uri serializes the port component of a URI without validating it. When recomposing the authority, the userinfo and host components are escaped but the port is concatenated verbatim, so a port value that is not a sequence of digits can inject authority delimiters, demoting the intended host to userinfo and pointing the authority at an attacker-controlled host. Both fast-uri and Node's URL read the result back as the attacker's host with no error, so re-validating the built URI does not catch it. This affects applications that build URIs from parts and assign untrusted data to the port component through the serialize, normalize, or equal functions in their object forms. The issue affects fast-uri versions before 2.4.6, from 3.0.0 before 3.1.7, and from 4.0.0 before 4.1.4. It is fixed in 2.4.6, 3.1.7, and 4.1.4, where recomposeAuthority rejects any port that is not a digit sequence per RFC 3986.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

fast-uri fast-uri

Default version status: unaffected

  • 0 to < 2.4.6affected
  • 2.4.6unaffected
  • 3.0.0 to < 3.1.7affected
  • 3.1.7unaffected
  • 4.0.0 to < 4.1.4affected
  • 4.1.4unaffected
pkg:npm/fast-uri

References