---
cve: "CVE-2026-6321"
severity: "HIGH"
cvss: 7.5
epss: "52%"
vendor: "fast-uri"
kev: false
exploited: false
published: "2026-05-04 19:31:57"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-03T21:52:41+02:00"
---

# CVE-2026-6321

> 7.5 HIGH · 🧪 PoC

## Beschreibung

fast-uri decoded percent-encoded path separators and dot segments before applying dot-segment removal in its normalize() and equal() functions. Encoded path data was treated like real slashes and parent-directory references, so distinct URIs could collapse onto the same normalized path. Applications that normalize or compare attacker-controlled URLs to enforce path-based policy can be bypassed, with a path that appears confined under an allowed prefix normalizing to a different location. Versions

## CVSS-Vektor

```
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Netzwerk | bad |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Keine | good |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Keine | good |

## Patch verfügbar (OSV)

- cea547c91c6aae610041b17b75792ca4aa035a6d (Commit)

## Referenzen

- <https://github.com/fastify/fast-uri/security/advisories/GHSA-q3j6-qgpj-74h6>
- <https://cna.openjsf.org/security-advisories.html>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-6321) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_