Vulnerability-Lookup

GHSA-JH84-7PCC-38GF

Vulnerability from github – Published: 2026-09-06 12:30 – Updated: 2026-09-06 12:30

Details

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.

Severity

5.9 (Medium)


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

8.2 (High)


                  
                    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

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JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-86253"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-22"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-06T12:17:16Z",
    "severity": "HIGH"
  },
  "details": "h3 (npm package) versions \u003c= 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.",
  "id": "GHSA-jh84-7pcc-38gf",
  "modified": "2026-09-06T12:30:23Z",
  "published": "2026-09-06T12:30:23Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/h3js/h3/security/advisories/GHSA-wr4h-v87w-p3r7"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-86253"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/h3-before-1.15.6-path-traversal-via-percent-encoded-dot-segments"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-86253 (GCVE-0-2026-86253)

Vulnerability from cvelistv5 – Published: 2026-09-06 12:00 – Updated: 2026-09-10 15:04

Title

h3 before 1.15.6 Path Traversal via Percent-Encoded Dot Segments

Summary

Severity

8.2 (High)


                        
                          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

5.9 (Medium)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-10 14:19 UTC

CWE

CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

Assigner

VulnCheck mitre root

References

2 references

URL	Tags
https://github.com/h3js/h3/security/advisories/GH…	vendor-advisory
https://www.vulncheck.com/advisories/h3-before-1.…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
h3js	h3	Affected: 0 , < 1.15.6 (semver) Unaffected: 1.15.6 (semver) Affected: 2.0.0-beta.0 , < 2.0.1-rc.15 (semver) Unaffected: 2.0.1-rc.15 (semver)

Date Public

2026-03-17 00:00

Credits

0xkakash1

Show details on NVD website

JSON

To clipboard

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  "containers": {
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                "id": "CVE-2026-86253",
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                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-10T14:19:05.242837Z",
                "version": "2.0.3"
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              "version": "0",
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            },
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      "references": [
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
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Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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GHSA-JH84-7PCC-38GF

CVE-2026-86253 (GCVE-0-2026-86253)

Tags

Sightings

Nomenclature

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