CVE-2026-6321
Medium
Elevated severity or exploit probability.
CVSS base
7.5
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS — probability of exploitation (30 days)
0.6%
48.7th percentile
CISA KEV
Not listed
Weakness / dates
CWE-22
Published 2026-05-04 · modified 2026-09-10
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | N | None |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | N | None |
| Integrity | H | High |
| Availability | N | None |
Timeline
- 2026-05-04 — Published (NVD)
- 2026-09-10 — Last modified (NVD)
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.
Affected
References
- https://cna.openjsf.org/security-advisories.html
- https://github.com/fastify/fast-uri/security/advisories/GHSA-q3j6-qgpj-74h6
- https://access.redhat.com/errata/RHSA-2026:19238
- https://access.redhat.com/errata/RHSA-2026:20338
- https://access.redhat.com/errata/RHSA-2026:21338
- https://access.redhat.com/errata/RHSA-2026:24473
- https://access.redhat.com/errata/RHSA-2026:24766
- https://access.redhat.com/errata/RHSA-2026:24866
- https://access.redhat.com/errata/RHSA-2026:24977
- https://access.redhat.com/errata/RHSA-2026:25089
- https://access.redhat.com/errata/RHSA-2026:25123
- https://access.redhat.com/errata/RHSA-2026:26214
- https://access.redhat.com/errata/RHSA-2026:26234
- https://access.redhat.com/errata/RHSA-2026:26416
- https://access.redhat.com/errata/RHSA-2026:26420
- https://access.redhat.com/errata/RHSA-2026:34342
- https://access.redhat.com/errata/RHSA-2026:37385
- https://access.redhat.com/errata/RHSA-2026:42078
- https://access.redhat.com/errata/RHSA-2026:42079
- https://access.redhat.com/errata/RHSA-2026:56366
- https://access.redhat.com/errata/RHSA-2026:56431
- https://access.redhat.com/errata/RHSA-2026:56928
- https://access.redhat.com/errata/RHSA-2026:57013
- https://access.redhat.com/security/cve/CVE-2026-6321
- https://bugzilla.redhat.com/show_bug.cgi?id=2466582
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6321.json