Horovod contains an insecure deserialization vulnerability in its KVStore HTTP server component
Critical9.8CVE-2026-31234 · Published May 12, 2026 · updated Jun 29, 2026
Affected versions
| Package | Affected | Fixed in |
|---|---|---|
| horovod PyPI | <= 0.28.1 | No fix yet |
Details and references
Horovod thru 0.28.1 contains an insecure deserialization vulnerability (CWE-502) in its KVStore HTTP server component. The KVStore server, used for distributed task coordination, lacks authentication and authorization controls, allowing any remote attacker to write arbitrary data via HTTP PUT requests. When a Horovod worker reads data from the KVStore (via HTTP GET), it deserializes the data using cloudpickle.loads() without verifying its source or integrity. An attacker can exploit this by sending a malicious pickle payload to the server before the legitimate data is written, causing the victim worker to deserialize and execute arbitrary code, leading to remote code execution.
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Severity from
- GitHub (reviewed advisory)
- Weakness
- CWE-502
- Also known as
- CVE-2026-31234, PYSEC-2026-354
More horovod advisories
All| Date | Advisory | Severity | Fixed in |
|---|---|---|---|
| Mar 202025 | Horovod Vulnerable to Command Injection CVE-2024-10190Critical9.8no fix yet | Critical9.8 | No fix yet |
| Mar 292022 | Use of insecure temporary file in Horovod CVE-2022-0315High8.2fixed in 0.24.0 | High8.2 | 0.24.0 |