GitHub Advisoryadvisory · npm
GHSA-v39h-62p7-jpjc fast-uri vulnerable to host confusion via percent-encoded authority delimiters
HIGH
Official page ↗
- Aliases
- CVE-2026-6322
- Ecosystem
- npm
- Packages
- fast-uri
- Severity
- High
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- Weaknesses
- CWE-140, CWE-436
- Reviewed
- 2026-05-08
Affected packages
• npm fast-uri: >= 3.0.0, < 3.1.2 → fixed in 3.1.2
• npm fast-uri: < 2.4.1 → fixed in 2.4.1
Description
Impact
`fast-uri` v3.1.1 and earlier decodes percent-encoded authority delimiters (`%40` as `@`, `%3A` as `:`) inside the host component and serializes them back as raw characters. This changes the URI structure, turning a hostname into userinfo plus a different host.
For example, `http://trusted.com%40evil.com/` normalizes to `http://[email protected]/`, which reparses as host `evil.com` with userinfo `trusted.com`.
Applications that normalize untrusted URLs before host allowlist checks, redirect validation, or outbound request routing can be steered to a different authority than the original URL appeared to contain.
Patches
Upgrade to `fast-uri` >= 3.1.2, or if you are in the v2.x release line, v2.4.1
Workarounds
None. Upgrade to the patched version.
Related
Alias · CVE (1)
- CVE-2026-6322 fast-uri normalize() decoded percent-encoded authority delimiters inside the host component and then re-emitted them as raw delimiters… vulnerability
References
- https://github.com/fastify/fast-uri/security/advisories/GHSA-v39h-62p7-jpjc web
- https://nvd.nist.gov/vuln/detail/CVE-2026-6322 advisory
- https://access.redhat.com/errata/RHSA-2026:41928 web
- https://access.redhat.com/errata/RHSA-2026:41951 web
- https://access.redhat.com/errata/RHSA-2026:42078 web
- https://access.redhat.com/errata/RHSA-2026:42142 web
- https://access.redhat.com/errata/RHSA-2026:43038 web
- https://access.redhat.com/errata/RHSA-2026:54395 web
- https://access.redhat.com/errata/RHSA-2026:54555 web
- https://access.redhat.com/errata/RHSA-2026:56366 web
- https://access.redhat.com/errata/RHSA-2026:56431 web
- https://access.redhat.com/errata/RHSA-2026:56928 web
- https://access.redhat.com/errata/RHSA-2026:56968 web
- https://access.redhat.com/errata/RHSA-2026:57013 web
- https://access.redhat.com/errata/RHSA-2026:57487 web
- https://access.redhat.com/errata/RHSA-2026:60520 web
- https://access.redhat.com/errata/RHSA-2026:60855 web
- https://access.redhat.com/errata/RHSA-2026:61783 web
- https://access.redhat.com/security/cve/CVE-2026-6322 web
- https://bugzilla.redhat.com/show_bug.cgi?id=2466684 web
- https://cna.openjsf.org/security-advisories.html web
- https://github.com/fastify/fast-uri package
- https://github.com/fastify/fast-uri/releases/tag/v2.4.1 web
- https://github.com/fastify/fast-uri/releases/tag/v3.1.2 web
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6322.json web
- https://access.redhat.com/errata/RHSA-2026:25271 web
- https://access.redhat.com/errata/RHSA-2026:25273 web
- https://access.redhat.com/errata/RHSA-2026:26225 web
- https://access.redhat.com/errata/RHSA-2026:26234 web
- https://access.redhat.com/errata/RHSA-2026:28571 web
- https://access.redhat.com/errata/RHSA-2026:29197 web
- https://access.redhat.com/errata/RHSA-2026:29795 web
- https://access.redhat.com/errata/RHSA-2026:29796 web
- https://access.redhat.com/errata/RHSA-2026:29800 web
- https://access.redhat.com/errata/RHSA-2026:29834 web
- https://access.redhat.com/errata/RHSA-2026:30076 web
- https://access.redhat.com/errata/RHSA-2026:33683 web
- https://access.redhat.com/errata/RHSA-2026:34160 web
- https://access.redhat.com/errata/RHSA-2026:34342 web
- https://access.redhat.com/errata/RHSA-2026:34374 web