# 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.

- **Severity:** Medium 6.5 (`CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 20 Mar 2025
- **Updated:** 15 Oct 2025
- **Also known as:** GHSA-m37h-8r48-2cxj, PYSEC-2026-1442

## 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 (Exposed Dangerous Method or Function)

## 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 | Ecosystem | 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: 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

- [CVE-2023-6016](https://insights.sbomify.com/CVE-2023-6016/): H2O Remote Code Execution via POJO Model Import (critical 10.0)
- [CVE-2025-6544](https://insights.sbomify.com/CVE-2025-6544/): Deserialization Vulnerability in h2oai/h2o-3 (critical 9.8)
- [CVE-2024-10553](https://insights.sbomify.com/CVE-2024-10553/): Jdbc Deserialization in h2oai/h2o-3 (critical 9.8)
- [CVE-2023-6569](https://insights.sbomify.com/CVE-2023-6569/): External Control of File Name or Path in h2oai/h2o-3 (critical 9.3)
- [CVE-2023-6013](https://insights.sbomify.com/CVE-2023-6013/): H2O Local File Include (critical 9.3)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2024-6863 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-6863 exists.

Affected packages and fixed versions:
- h2o (PyPI): affected from 3.32.1.2 up to 3.46.0; no fix listed
- h2o (PyPI): affected from 3.32.1.2 up to 3.46.0; no fix listed
- h2o (PyPI): affected from 3.32.1.2 up to 3.46.0; no fix listed
- ai.h2o:h2o-core (Maven): affected from 3.32.1.2 up to 3.46.0; no fix listed
- ai.h2o:h2o-core (Maven): affected from 3.32.1.2 up to 3.46.0; no fix listed

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2024-6863/ (Markdown: https://insights.sbomify.com/CVE-2024-6863/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-6863
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-6863
- OSV: https://osv.dev/vulnerability/CVE-2024-6863

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-6863/
Summaries are generated and may contain mistakes; the official description above is the record.