CVE-2024-6863 Encryption of Arbitrary Files with Attacker-Controlled Key in h2oai/h2o-3
Attackers can encrypt arbitrary server files with attacker-controlled keys, causing ransomware-like data loss and denial of service.
- 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-2024-6863?
CVE-2024-6863 is a medium-severity vulnerability in h2oai/h2o-3, published on 20 Mar 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
In h2oai/h2o-3 version 3.46.0, an endpoint exposing a custom EncryptionTool allows an attacker to encrypt any files on the target server with a key of their choosing. The chosen key can also be overwritten, resulting in ransomware-like behavior. This vulnerability makes it possible for an attacker to encrypt arbitrary files with keys of their choice, making it exceedingly difficult for the target to recover the keys needed for decryption.
Weakness: CWE-749
Which versions are affected by CVE-2024-6863?
5 open source packages ship an affected version, including h2o and ai.h2o:h2o-core. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
h2o PyPI | From 3.32.1.2 to 3.46.0 | None |
h2o PyPI | From 3.32.1.2 to 3.46.0 | None |
h2o PyPI | From 3.32.1.2 to 3.46.0 | None |
ai.h2o:h2o-core Maven | From 3.32.1.2 to 3.46.0 | None |
ai.h2o:h2o-core Maven | From 3.32.1.2 to 3.46.0 | None |
Products include H2o H2o.
How do I fix CVE-2024-6863?
No fix has been published for CVE-2024-6863 yet. Limit exposure of the affected software until one is available.
Is CVE-2024-6863 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-6863 exists.
Other vulnerabilities in h2oai/h2o-3
Sources
Also known as GHSA-m37h-8r48-2cxj, PYSEC-2026-1442.