{"id":"CVE-2026-44552","aliases":["GHSA-3x8w-4f7p-xxc2","PYSEC-2026-2696"],"url":"https://o3.security/vulnerability/CVE-2026-44552","summary":"Open WebUI: Redis Cache Keys tool_servers and terminal_servers Missing Instance Prefix Enable Cross-Instance Cache Poisoning","details":"Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the tool_servers and terminal_servers keys in utils/tools.py do use a prefix. When two or more Open WebUI instances share a Redis database (a supported and documented deployment pattern, e.g., for multi-region deployments, blue-green setups, or cluster topologies), the unprefixed keys collide. An admin on Instance A writing to tool_servers overwrites the value read by Instance B — causing Instance B's users to receive Instance A's tool server configuration. This vulnerability is fixed in 0.9.0.","published":"2026-05-15T19:57:22.801Z","modified":"2026-08-07T11:31:09.893757377Z","cvss":{"score":8.7,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"open-webui","fixedVersion":"0.9.0"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44552.json"},{"type":"ADVISORY","url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-3x8w-4f7p-xxc2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44552"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:31:09.893757377Z"}}