fast-uri vulnerable to host confusion via percent-encoded authority delimiters
Summary
| CVE | CVE-2026-6322 |
|---|---|
| State | PUBLISHED |
| Assigner | openjs |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-05 11:16:33 UTC |
| Updated | 2026-05-12 19:11:31 UTC |
| Description | fast-uri normalize() decoded percent-encoded authority delimiters inside the host component and then re-emitted them as raw delimiters during serialization. A host that combined an allowed domain, an encoded at-sign, and a different domain was re-emitted with the at-sign as a raw userinfo separator, changing the URI's authority to the second domain. Applications that normalize untrusted URLs before host allowlist checks, redirect validation, or outbound request routing can be steered to a different authority than the input appeared to specify. Versions <= 3.1.1 are affected. Update to 3.1.2 or later. |
Risk And Classification
Primary CVSS: v3.1 7.5 HIGH from ce714d77-add3-4f53-aff5-83d477b104bb
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS: 0.000380000 probability, percentile 0.113380000 (date 2026-05-12)
Problem Types: CWE-436 | CWE-436 CWE-436: Interpretation Conflict
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | ce714d77-add3-4f53-aff5-83d477b104bb | Secondary | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| 3.1 | CNA | CVSS | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
HighAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD Known Affected Configurations (CPE 2.3)
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| cna.openjsf.org/security-advisories.html | ce714d77-add3-4f53-aff5-83d477b104bb | cna.openjsf.org | Vendor Advisory |
| github.com/fastify/fast-uri/security/advisories/GHSA-v39h-62p7-jpjc | ce714d77-add3-4f53-aff5-83d477b104bb | github.com | Vendor Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Jvr (en)
CNA: Matteo Collina (en)
CNA: Ulises Gascón (en)
CNA: KaKa (en)
There are currently no legacy QID mappings associated with this CVE.