CVE-2024-5986Network attack vector

Unauthenticated file overwrite via frame export path

Published Feb 2, 2026 · Updated Feb 2, 2026

Arbitrary file write in H2O.ai H2O-3 3.46.0.1 allows remote attackers to overwrite server files through unauthenticated REST requests. The /3/Parse endpoint accepts attacker-controlled header data for an empty frame, and /3/Frames/{frame_id}/export writes it to an attacker-selected filesystem path. Network access to an open H2O-3 REST API is sufficient; overwriting scripts or access-control files grants code execution with H2O-3 process privileges.

CVSS severity9.1
Critical
EPSS probability0.65%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Arbitrary file write in H2O.ai H2O-3 3.46.0.1 allows remote attackers to overwrite server files through unauthenticated REST requests. The /3/Parse endpoint accepts attacker-controlled header data for an empty frame, and /3/Frames/{frame_id}/export writes it to an attacker-selected filesystem path. Network access to an open H2O-3 REST API is sufficient; overwriting scripts or access-control files grants code execution with H2O-3 process privileges.

The record

CVE
CVE-2024-5986
Published
Feb 2, 2026
Updated
Feb 2, 2026
Vendor
H2O.ai
Product
H2O-3
Classifications
CWE-73, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Feb 2, 2026CVE publishedPublication date reported by the CVE source.
  2. Feb 2, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=unspecified <=latest

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

H2O.ai · H2O-3version=unspecified <=latest

Published CVSS scores

9.1GitHub Advisory DatabaseCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-73External Control of File Name or Path
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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