High
h3 before 1.15.6 Path Traversal via Percent-Encoded Dot Segments
Type: advisorySources: OSV
h3 (npm package) versions <= 2.0.1-rc.14 contain a path traversal vulnerability in serveStatic(). On Node.js deployments, event.url.pathname is not normalized, so percent-encoded dot segments (%2e%2e) are passed to decodeURI() and decoded to ../ sequences without sanitization. An unauthenticated remote attacker can send crafted requests to endpoints served by serveStatic() to read arbitrary files outside the intended static directory. Fixed in 1.15.6 and 2.0.1-rc.15.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-86253
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 3 Nov 2026, 10:03 UTC · Revision 1
Source evidence
h3 before 1.15.6 Path Traversal via Percent-Encoded Dot Segments
core-osv · Original sourcePublished 6 Sept 2026, 12:00 UTC
h3 (npm package) versions <= 2.0.1-rc.14 contain a path traversal vulnerability in serveStatic(). On Node.js deployments, event.url.pathname is not normalized, so percent-encoded dot segments (%2e%2e) are passed to decodeURI() and decoded to ../ sequences without sanitization. An unauthenticated remote attacker can send crafted requests to endpoints served by serveStatic() to read arbitrary files outside the intended static directory. Fixed in 1.15.6 and 2.0.1-rc.15.
osv:CVE-2026-86253
Complete source record
{
"id": "8d9ddebb8bcb94b95e88ec4ca08c17a7b083c6b55ef10e406b8f5263ef63d9fc",
"url": "https://osv.dev/vulnerability/CVE-2026-86253",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "h3 before 1.15.6 Path Traversal via Percent-Encoded Dot Segments",
"summary": "h3 (npm package) versions <= 2.0.1-rc.14 contain a path traversal vulnerability in serveStatic(). On Node.js deployments, event.url.pathname is not normalized, so percent-encoded dot segments (%2e%2e) are passed to decodeURI() and decoded to ../ sequences without sanitization. An unauthenticated remote attacker can send crafted requests to endpoints served by serveStatic() to read arbitrary files outside the intended static directory. Fixed in 1.15.6 and 2.0.1-rc.15.",
"evidence": "osv:CVE-2026-86253",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-86253",
"aliases": [
"CVE-2026-86253",
"GHSA-wr4h-v87w-p3r7"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/h3js/h3",
"type": "GIT",
"events": [
{
"introduced": "0"
},
{
"fixed": "829daf157e5add61d60fb18dfdd9f6885e57a5e3"
},
{
"introduced": "8120545c3ce65f0149f59d72d4db7cb1a53b83e3"
},
{
"fixed": "91361835657410605f2041762da9e3f60d24ecfb"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"introduced": "0"
},
{
"fixed": "1.15.6"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
},
{
"range": [
{
"introduced": "2.0.0-beta.0"
},
{
"fixed": "2.0.1-rc.15"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
}
]
}
}
],
"versions": [
"v1.15.5",
"v2.0.1-rc.14",
"v2.0.1-rc.13",
"v2.0.1-rc.12",
"v2.0.1-rc.11",
"v2.0.1-rc.10",
"v2.0.1-rc.9",
"v2.0.1-rc.8",
"v2.0.1-rc.7",
"v2.0.1-rc.6",
"v2.0.1-rc.5",
"v2.0.1-rc.4",
"v2.0.1-rc.3",
"v2.0.1-rc.2",
"v2.0.0-rc.1",
"v2.0.0-beta.5",
"v1.15.4",
"v2.0.0-beta.4",
"v2.0.0-beta.3",
"v2.0.0-beta.2",
"v2.0.0-beta.1",
"v2.0.0-beta.0",
"v1.15.2",
"v1.15.1",
"v1.15.0",
"v1.14.0",
"v1.13.1",
"v1.13.0",
"v1.12.0",
"v1.11.1",
"v1.11.0",
"v1.10.2",
"v1.10.1",
"v1.10.0",
"v1.9.0",
"v1.8.2",
"v1.8.1",
"v1.8.0",
"v1.8.0-rc.3",
"v1.8.0-rc.2",
"v1.8.0-rc.1",
"v1.8.0-rc.0",
"v1.7.1",
"v1.7.0",
"v1.6.6",
"v1.6.5",
"v1.6.4",
"v1.6.3",
"v1.6.2",
"v1.6.1",
"v1.6.0",
"v1.5.0",
"v1.4.0",
"v1.3.0",
"v1.2.1",
"v1.2.0",
"v1.1.0",
"v1.0.2",
"v1.0.1",
"v1.0.0",
"v0.8.6",
"v0.8.5",
"v0.8.4",
"v0.8.3",
"v0.8.2",
"v0.8.1",
"v0.8.0",
"v0.7.21",
"v0.7.20",
"v0.7.19",
"v0.7.18",
"v0.7.17",
"v0.7.16",
"v0.7.15",
"v0.7.14",
"v0.7.13",
"v0.7.12",
"v0.7.11",
"v0.7.10",
"v0.7.9",
"v0.7.8",
"v0.7.7",
"v0.7.6",
"v0.7.5",
"v0.7.4",
"v0.7.3",
"v0.7.2",
"v0.7.1",
"v0.7.0",
"v0.6.0",
"v0.5.7",
"v0.5.6",
"v0.5.5",
"v0.5.4",
"v0.5.3",
"v0.5.2",
"v0.5.1",
"v0.5.0",
"v0.4.2",
"v0.4.1",
"v0.4.0",
"v0.3.9",
"v0.3.8",
"v0.3.7",
"v0.3.6",
"v0.3.5",
"v0.3.4",
"v0.3.3",
"v0.3.2",
"v0.3.1",
"v0.3.0",
"v0.2.12",
"v0.2.11",
"v0.2.10",
"v0.2.9",
"v0.2.8",
"v0.2.7",
"v0.2.6",
"v0.2.5",
"v0.2.4",
"v0.2.3",
"v0.2.2",
"v0.2.1",
"v0.2.0",
"v0.0.15",
"v0.0.14",
"v0.0.13",
"v0.0.12",
"v0.0.11",
"v0.0.10",
"v0.0.9",
"v0.0.8",
"v0.0.7",
"v0.0.6",
"v0.0.5",
"v0.0.4",
"v0.0.3",
"v0.0.2",
"v0.0.1"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-86253.json"
}
}
],
"modified": "2026-10-28T02:30:27.844873201Z",
"provider": "osv",
"references": [
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86253.json",
"https://github.com/h3js/h3/security/advisories/GHSA-wr4h-v87w-p3r7",
"https://nvd.nist.gov/vuln/detail/CVE-2026-86253",
"https://www.vulncheck.com/advisories/h3-before-1.15.6-path-traversal-via-percent-encoded-dot-segments"
],
"provider_metadata": {
"cwe_ids": [
"CWE-22"
],
"cna_assigner": "VulnCheck",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86253.json"
}
},
"related_cves": [
{
"value": "CVE-2026-86253",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 494361,
"published_at": "2026-09-06T12:00:28.232+00:00"
}