CVE-2024-5986: Ai.h2o:h2o core: H2O has an External Control of File Name or Path vulnerability
Affects ai.h2o:h2o-coreSource GCVE Database
Not known to be exploited · CVSS 9.1 Critical.
Data as of 27 Oct 2026, 17:30 UTC
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 2 Feb 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Mavenai.h2o:h2o-core | Affected
| Fixed in– |
| PyPIh2o | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Until a fix is available, restrict access to the vulnerable endpoints and monitor for suspicious activity related to file exports.
Description
CVE-2024-5986 is a critical vulnerability in h2oai/h2o-3 version 3.46.0.1 and earlier that allows remote attackers to write arbitrary data to any file on the server. This is done by exploiting the /3/Parse endpoint to inject attacker-controlled data as the header of an empty file, which can then be exported via the /3/Frames/framename/export endpoint. The vulnerability can lead to remote code execution and full system compromise by overwriting critical files such as private SSH keys or scripts.
References
- nvd.nist.gov/vuln/detail/CVE-2024-5986 (opens in a new tab)
- github.com/h2oai/h2o-3 (opens in a new tab)
- github.com/pypa/advisory-database/tree/main/vulns/h2o/PYSEC-2026-353.yaml (opens in a new tab)
- huntr.com/bounties/64ff5319-6ac3-4447-87f7-b53495d4d5a3 (opens in a new tab)
- pypi.org/project/h2o (opens in a new tab)