{"cve":"CVE-2026-45398","nvd":{"published":"2026-05-15T21:16:37.863","modified":"2026-06-17T10:52:00.947","status":"Analyzed","description":"Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, _validate_collection_access() checks the user-memory-* and file-* collection name prefixes but does not check knowledge base collections, which use raw UUIDs as collection names. Any authenticated user who knows a private knowledge base UUID can read its content through the retrieval query endpoints, even though the knowledge API correctly denies that user access. The same gap affects the retrieval write endpoints (/process/text, /process/file, /process/files/batch, /process/web, /process/youtube), allowing an attacker to inject content into or overwrite another user's knowledge base. This vulnerability is fixed in 0.9.5.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.5},"cwes":["CWE-639"],"references":["https://github.com/open-webui/open-webui/pull/22109","https://github.com/open-webui/open-webui/releases/tag/v0.9.5","https://github.com/open-webui/open-webui/security/advisories/GHSA-4g37-7p2c-38r9","https://github.com/open-webui/open-webui/security/advisories/GHSA-4g37-7p2c-38r9"],"products":["openwebui:open_webui"],"source":"nvd","synced_at":"2026-10-19T22:35:16.954578616+00:00"},"epss":{"cve":"CVE-2026-45398","score":0.00331,"percentile":0.26245,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-4g37-7p2c-38r9","url":"https://osv.dev/vulnerability/GHSA-4g37-7p2c-38r9","summary":"Open WebUI Vulnerable to IDOR: Retrieval API Bypasses Knowledge Base Access Controls","modified":"2026-07-13T16:43:03.444134619Z","packages":[{"ecosystem":"PyPI","name":"open-webui","purl":"pkg:pypi/open-webui","ranges":["<0.9.5"],"fixed":["0.9.5"]}]},{"id":"PYSEC-2026-2699","url":"https://osv.dev/vulnerability/PYSEC-2026-2699","summary":"Open WebUI Vulnerable to IDOR: Retrieval API Bypasses Knowledge Base Access Controls","modified":"2026-07-13T16:31:52.296508221Z","packages":[{"ecosystem":"PyPI","name":"open-webui","purl":"pkg:pypi/open-webui","ranges":["<0.9.5"],"fixed":["0.9.5"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}