CVE-2026-6321

Name	CVE-2026-6321
Description	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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
node-ajv (PTS)	bullseye	6.12.6-2	vulnerable
	bookworm	6.12.6-3	vulnerable
	trixie	8.12.0~ds+~2.1.1-5	vulnerable
	forky, sid	8.18.0~ds+~cs6.1.1-2	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
node-ajv	source	(unstable)	(unfixed)

Notes

https://github.com/fastify/fast-uri/security/advisories/GHSA-q3j6-qgpj-74h6
Fixed by: https://github.com/fastify/fast-uri/commit/876ce79b662c3e5015e4e7dffe6f37752ad34f35 (v3.1.1)
Embedded fast-uri used and provided as node-fast-uri