CWE-73Weakness · CWE-73

CVE-2024-5986

CRITICAL · 9.1 CVSS v3.0 Published 2026-02-02
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A vulnerability in h2oai/h2o-3 version 3.46.0.1 allows remote attackers to write arbitrary data to any file on the server. This is achieved by exploiting the `/3/Parse` endpoint to inject attacker-controlled data as the header of an empty file, which is then exported using the `/3/Frames/framename/export` endpoint. The impact of this vulnerability includes the potential for remote code execution and complete access to the system running h2o-3, as attackers can overwrite critical files such as private SSH keys or script files.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A path traversal/file injection vulnerability in h2oai/h2o-3 v3.46.0.1 allows remote attackers to write arbitrary data to any file on the server by injecting attacker-controlled content as a file header via the /3/Parse endpoint, then exporting it to an arbitrary location using /3/Frames/framename/export. This enables overwriting critical system files for potential remote code execution.

MitigationUpgrade h2o-3 to a patched version; if immediate upgrade is not feasible, restrict network access to the /3/Parse and /3/Frames/*/export endpoints and implement strict file write validation.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the installed h2o-3 version
    Run 'h2o --version' or check the H2O jar file name/version metadata in your deployment
    Affected if The version is 3.46.0.1 exactly, or falls within the 3.46.x branch prior to patching
  2. Verify network exposure of the /3/Parse endpoint
    Review your firewall rules, reverse proxy configuration, or security group settings to determine if port/service hosting /3/Parse is reachable from untrusted networks
    Affected if The /3/Parse endpoint is exposed to the internet or untrusted external networks
  3. Verify network exposure of the /3/Frames/*/export endpoint
    Review network access controls to determine if the /3/Frames/*/export endpoint is reachable from untrusted networks
    Affected if The /3/Frames/*/export endpoint is exposed to the internet or untrusted external networks
  4. Review H2O server logs for suspicious parse and export operations
    Examine H2O logs (stdout, file logs, or logging backend) for entries involving /3/Parse and /3/Frames/*/export with unexpected file paths or destinations
    Affected if Logs show export operations to paths outside the intended H2O data directory or to system directories such as /etc, /usr, or /opt
  5. Inspect the H2O data directory for unexpected files
    List files in the configured H2O frame storage directory and check for recently created files in system directories or config paths that should not be writable by the H2O service
    Affected if Unexpected files appear in sensitive system directories or configuration files have been modified outside of normal H2O operation

You are affected if h2o-3 version 3.46.0.1 is running AND either the /3/Parse or /3/Frames/*/export endpoints are network-accessible to untrusted users.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade h2o-3 to a patched version; if immediate upgrade is not feasible, restrict network access to the /3/Parse and /3/Frames/*/export endpoints and implement strict file write validation.

Have this fixed Scoped from the published advisory
  • Consultation6.0 h
  • Implementation8.0 h
  • Testing8.0 h
  • Review / QA4.0 h
26.0 hours of engineering $4,560
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-5986 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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