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TI-2026-59039 Aliases CVE-2026-86253GHSA-jh84-7pcc-38gf

h3 before 1.15.6 Path Traversal via Percent-Encoded Dot Segments

Priority LOW 37CWE-22Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Attack requirements
Present
Impact type
Information disclosure
Confidentiality · integrity · availability
High · None · None
Fix status
Partial Red Hat: 1 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-22 and the CVSS impact.

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00618 49th percentileScored 2026-11-07
Fix Partial h3 (h3js): 1.15.6, 2.0.1-rc.15Red Hat: 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
h3jsh3before 1.15.6; 2.0.0-beta.0 to before 2.0.1-rc.151.15.6, 2.0.1-rc.15Patch availableCNA
  • h3 Vendorh3js Affected before 1.15.6; 2.0.0-beta.0 to before 2.0.1-rc.15 Fixed in 1.15.6, 2.0.1-rc.15 Patch available CNA

CPE names Threatist (inferred) · 1

Inferred from how NVD named this product before; not given by a source.

CPEVersionsRoleVendor
cpe:2.3:a:h3:h3:*:*:*:*:*:*:*:*——h3js
  • cpe:2.3:a:h3:h3:*:*:*:*:*:*:*:* Versions — — ·h3js

Remediation

  • Fix · CNA h3 (h3js) Fixed in 1.15.6, 2.0.1-rc.15

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet: Fix deferred

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-86253
  2. 2026-10-03 Alias added: GHSA-jh84-7pcc-38gf

References

Advisory 1

  • TI-2026-25559 h3 has a Server-Sent Events Injection via Unsanitized Newlines in Event Stream Fields CVSS 3.1CRITICAL 10.0
  • TI-2026-25562 h3 has a middleware bypass with one gadget CVSS 3.1CRITICAL 9.1
  • TI-2026-59038 h3 before 1.15.9 SSE Event Injection via Carriage Return CVSS 4.0MEDIUM 6.9
  • TI-2026-59037 h3 before 1.15.9 Path Traversal via Double Decoding CVSS 4.0HIGH 8.2
  • TI-2026-25560 h3 has an observable timing discrepancy in basic auth utils CVSS 3.1MEDIUM 5.9
  • TI-2026-58994 h3 before 2.0.1-rc.18 Open Redirect via redirectBack() CVSS 4.0MEDIUM 5.3
See all 10 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences