CVE-2024-5986 Remote Arbitrary File Write with Arbitrary Data in h2oai/h2o-3
Remote attackers can write arbitrary data to any file on the server via the Parse and export endpoints, potentially leading to remote code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2024-5986?
CVE-2024-5986 is a critical path traversal vulnerability in h2oai/h2o-3, published on 2 Feb 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-73
Which versions are affected by CVE-2024-5986?
5 open source packages ship an affected version, including h2o and ai.h2o:h2o-core.
| Package | Affected | Fixed in |
|---|---|---|
h2o PyPI | All versions to 3.46.0.1 | None |
h2o PyPI | All versions to 3.46.0.1 | None |
h2o PyPI | All versions to 3.46.0.1 | None |
ai.h2o:h2o-core Maven | All versions to 3.46.0.1 | None |
ai.h2o:h2o-core Maven | All versions to 3.46.0.1 | None |
How do I fix CVE-2024-5986?
No fix has been published for CVE-2024-5986 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2024-5986 being exploited?
There is no known exploitation of CVE-2024-5986 in the wild and no public exploit code.
Sources
Also known as GHSA-wj3h-wx8g-x699, PYSEC-2026-353.