fast-uri vulnerable to host confusion via an unclosed bracket in the URI authority (fast-uri fast-uri)

CVE-2026-84394
HIGH 7.5

At a glance

Source
NVD
EPSS
EPSS 0.38 % · percentile 32 ()
State
PUBLISHED
Published
Updated
Assigner
openjs
NVD status
Analyzed

Description

fast-uri accepts a host that contains an unbalanced or misplaced authority bracket without reporting an error. A host that starts with an opening bracket but does not end with a closing bracket is neither validated as an IP literal nor canonicalized as a domain name, so parse() returns it as the host with error undefined, while Node's URL and the HTTP clients built on it resolve the same string to a different host. An application that reads the parsed host to make a host decision, such as an SSRF denylist, a redirect allowlist, or proxy routing, and then passes the original URL to an HTTP client evaluates its policy against a string that is not the host the request reaches. The same host is carried through normalize, equal, and resolve. This affects fast-uri versions 2.4.5, 3.1.6, and 4.1.3, and is fixed in 2.4.6, 3.1.7, and 4.1.4, where parse() reports a malformed host for any host that contains a bracket but is not a valid IPv6 literal.

Weaknesses (CWE)

  • CWE-436 — Interpretation Conflict

References

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:Nopenjs
CVSS 3.1HIGH 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:NNVD · ce714d77-add3-4f53-aff5-83d477b104bb (Secondary)

Advisories

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
fast-uri · fast-uriaffected 2.4.5 < 2.4.6 ; unaffected 2.4.6 ; affected 3.1.6 < 3.1.7 ; unaffected 3.1.7 ; affected 4.1.3 < 4.1.4 ; unaffected 4.1.4

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD