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🛡️ CVE-2024-5986 — h2o

🔴 CVSS 9.5 — Critical ✅ No Known Exploit CWE-73 NVD
9.5
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

H2O has an External Control of File Name or Path vulnerability

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.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity high, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: None — an unauthenticated stranger can try it.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: None.
  • Integrity impact: High — total loss, or loss the attacker controls.
  • Availability impact: High — total loss, or loss the attacker controls.

Weakness class

CVE-2024-5986 is classified as CWE-73: External Control of File Name or Path. A caller can influence which file the application opens or writes, extending an operation to files that were never meant to be reachable.

Affected software

CVE-2024-5986 is recorded against 3 packages.

  • ai.h2o:h2o-core
  • h2o
  • unknown

Timeline and source

Published on 2 February 2026 and last revised on 29 June 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

nvd.nist.gov (Advisory)
github.com (Package)
huntr.com (Web)

Other advisories for this package

ai.h2o:h2o-core has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-73: External Control of File Name or Path) in other software:

Details

Severity CRITICAL
CVSS Score 9.5
CVSS Vector CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
CWE CWE-73
Public Exploit ✅ No
Source NVD
Published 2026-02-02
Updated 2026-08-20
Modified 2026-06-29
Fix URL N/A

Affected Packages

Software From version Fixed in
ai.h2o:h2o-core — —
h2o — —
unknown — —

Similar Threats

Exploit Protection

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CVE-2024-5986 carries CVSS 9.5 Critical rating. BotEraser checks your installation against this and other known CVE records, and blocks IPs associated with exploit activity.

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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