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TI-2023-14626 Aliases CVE-2023-30847

H2O vulnerable to read from uninitialized pointer in the reverse proxy handler

Priority MEDIUM 43CWE-824Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
Low · None · High
Fix status
No fix listed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA.

Summary

H2O is an HTTP server. In versions 2.3.0-beta2 and prior, when the reverse proxy handler tries to processes a certain type of invalid HTTP request, it tries to build an upstream URL by reading from uninitialized pointer. This behavior can lead to crashes or leak of information to back end HTTP servers. Pull request number 3229 fixes the issue. The pull request has been merged to the `master` branch in commit f010336. Users should upgrade to commit f010336 or later.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00902 59th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
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
h2oaih2oup to 2.3.0-beta2—No fix listedCNA
  • h2o Vendorh2oai Affected up to 2.3.0-beta2 Fixed in — No fix listed CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:a:dena:h2o:*:*:*:*:*:*:*:*up to 2.2.6VulnerableKazuho Oku
cpe:2.3:a:dena:h2o:2.3.0:beta1:*:*:*:*:*:*2.3.0 beta1VulnerableKazuho Oku
cpe:2.3:a:dena:h2o:2.3.0:beta2:*:*:*:*:*:*2.3.0 beta2VulnerableKazuho Oku
  • cpe:2.3:a:dena:h2o:*:*:*:*:*:*:*:* Versions up to 2.2.6 Vulnerable ·Kazuho Oku
  • cpe:2.3:a:dena:h2o:2.3.0:beta1:*:*:*:*:*:* Versions 2.3.0 beta1 Vulnerable ·Kazuho Oku
  • cpe:2.3:a:dena:h2o:2.3.0:beta2:*:*:*:*:*:* Versions 2.3.0 beta2 Vulnerable ·Kazuho Oku

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2023-30847

References

Patch 2

Advisory 1

  • TI-2025-05944 Deserialization Vulnerability in h2oai/h2o-3 CVSS 3.0CRITICAL 9.8
  • TI-2025-05102 Deserialization Vulnerability in h2oai/h2o-3 CVSS 3.0CRITICAL 9.8
  • TI-2024-09776 Jdbc Deserialization in h2oai/h2o-3 CVSS 3.0CRITICAL 9.8
  • TI-2026-46834 h2oGPT 0.2.1 Path Traversal via OpenAI-compatible Files API CVSS 4.0CRITICAL 9.3
  • TI-2024-30727 H2O.ai H2O through 3.46.0.4 allows attackers to arbitrarily set the JDBC URL, leading to… CVSS 3.1CRITICAL 9.1
  • TI-2026-03424 Remote Code Execution in h2oai/h2o-3 CVSS 3.1CRITICAL 9.8
See all 52 →

Sources

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