CVE-2026-6321

HIGH 7.5

fast-uri vulnerable to path traversal via percent-encoded dot segments

CVSS Score

7.5

EPSS Score

0.0%

EPSS Percentile

0th

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 <= 3.1.0 are affected. Update to 3.1.1 or later.

CWE	CWE-22
Vendor	fast-uri
Product	fast-uri
Published	May 4, 2026

Stay Ahead of the Next One

Get instant alerts for fast-uri fast-uri

Be the first to know when new high vulnerabilities affecting fast-uri fast-uri are published — delivered to Slack, Telegram or Discord.

Get Free Alerts → Free · No credit card · 60 sec setup

CVSS v3 Breakdown

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

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Scope

Confidentiality

Integrity

Availability

Affected Versions

fast-uri / fast-uri

0 < 3.1.1

References

NVD ↗ CVE.org ↗ EPSS Data ↗

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

Credits

🔍 Jvr Matteo Collina Ulises Gascón KaKa