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☕ Maven🐍 PyPI
Not in CISA KEV
MEDIUM severity

CVE-2024-6863 — h2o-core

MEDIUM

CVE-2024-6863 is a medium-severity (CVSS 6.5) CWE-749 vulnerability in ai.h2o:h2o-core. The records list no fixed version yet; check the vendor advisory below and apply the mitigations in the meantime.

H2O Vulnerable to Execution of Arbitrary Files

Also known asPYSEC-2026-1442
Published
Updated
Affected
2 pkgs
Patched
See advisory
Exploits
None indexed
Exploitation data as of Oct 24, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

  • CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
  • CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.

Exploitation and automatability from CISA’s SSVC triage for CVE-2024-6863.

EPSS Exploitation Probability

via FIRST.org ↗
0.4%probability of exploitation in next 30 days
Lower Risk+0.01%
Lower risk than most CVEs28th percentile — riskier than 28% of all scored CVEsHighest risk
0.00%0.29%0.57%0.86%0.1%0.4%Apr 26Aug 26Oct 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

2 pkgs affected
☕ai.h2o:h2o-core🐍h2o

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven, PyPI packages — download data is not available via public APIs for these ecosystems.

Description

In h2oai/h2o-3 version 3.46.0, an endpoint exposing a custom EncryptionTool allows an attacker to encrypt any files on the target server with a key of their choosing. The chosen key can also be overwritten, resulting in ransomware-like behavior. This vulnerability makes it possible for an attacker to encrypt arbitrary files with keys of their choice, making it exceedingly difficult for the target to recover the keys needed for decryption.

Affected Packages

2 total
EcosystemPackageVulnerable rangeFix
☕Mavenai.h2o:h2o-core≥ 3.32.1.2No fix
🐍PyPIh2o≥ 3.32.1.2No fix

Affected Products

1 product · 1 configurations
Application
h2oh2o
1 version
3.46.0

Detection & mitigation playbook

Open-source dependency

  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ai.h2o:h2o-core, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Remediation status

    The records we use list no patched version of ai.h2o:h2o-core for CVE-2024-6863. Check the maintainer's advisory, and where your build allows, override or pin the dependency away from the vulnerable range.

  3. Mitigate without a patch

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

Frequently Asked Questions

In h2oai/h2o-3 version 3.46.0, an endpoint exposing a custom EncryptionTool allows an attacker to encrypt any files on the target server with a key of their choosing. The chosen key can also be overwritten, resulting in ransomware-like behavior. This vulnerability makes it possible for an attacker to encrypt arbitrary files with keys of their choice, making it exceedingly difficult for the target to recover the keys needed for decryption.
O3 Security · Impact-Aware SCA

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CVE-2024-6863: h2o-core (Medium 6.5)