fast-uri vulnerable to path traversal via percent-encoded dot segments
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.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-6321
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 07:35 UTC · Revision 1
Source evidence
fast-uri vulnerable to path traversal via percent-encoded dot segments
core-osv · Original sourcePublished 4 May 2026, 19:31 UTC
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.
osv:CVE-2026-6321
Complete source record
{
"id": "05b939fdec93cf93d4425af950d0343953ded43d9b75a30575fc94d41b0867e2",
"url": "https://osv.dev/vulnerability/CVE-2026-6321",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "fast-uri vulnerable to path traversal via percent-encoded dot segments",
"summary": "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.",
"evidence": "osv:CVE-2026-6321",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-6321",
"aliases": [
"CVE-2026-6321",
"GHSA-q3j6-qgpj-74h6"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/fastify/fast-uri",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "cea547c91c6aae610041b17b75792ca4aa035a6d"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "3.1.1"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
},
{
"cpe": "cpe:2.3:a:openjsf:fast-uri:*:*:*:*:*:node.js:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "3.1.1"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"v3.1.0",
"v3.0.6",
"v3.0.5",
"v3.0.4",
"v3.0.3",
"v3.0.2",
"v3.0.1",
"v3.0.0",
"v2.4.0",
"v2.3.1",
"v2.3.0",
"v2.2.0",
"v2.1.0",
"v2.0.0",
"v1.0.1",
"v1.0.0",
"v0.0.2",
"v0.0.1"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-6321.json"
}
}
],
"modified": "2026-10-28T02:30:26.872579287Z",
"provider": "osv",
"references": [
"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6321.json",
"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://cna.openjsf.org/security-advisories.html",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6321.json",
"https://github.com/fastify/fast-uri/security/advisories/GHSA-q3j6-qgpj-74h6",
"https://nvd.nist.gov/vuln/detail/CVE-2026-6321",
"https://bugzilla.redhat.com/show_bug.cgi?id=2466582"
],
"provider_metadata": {
"cwe_ids": [
"CWE-22"
],
"cna_assigner": "openjs",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/6xxx/CVE-2026-6321.json"
}
},
"related_cves": [
{
"value": "CVE-2026-6321",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 493400,
"published_at": "2026-05-04T19:31:57.253+00:00"
}