Deserialization in N/a
CVE-2026-31234
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.
Vulnerability class: Insecure Deserialization
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.010 (62.3th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 62nd percentile — 62.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.010 · change: +0.003
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-31234?
- CVE-2026-31234 is a critical-severity vulnerability in N/a, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2026-05-12.
- How severe is CVE-2026-31234?
- Critical severity. CVSS v3 base score is 9.8 out of 10.