{"id":"CVE-2026-88002","aliases":["GHSA-jqhh-cjmq-vmv6","PYSEC-2026-3879"],"url":"https://o3.security/vulnerability/CVE-2026-88002","summary":"Open WebUI: Any authenticated user can hang the server via a cyclic chat message history","details":"Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.5.0 until 0.11.1, the message-chain reconstruction helper in backend/open_webui/utils/misc.py advanced through a chat history by map key but tracked visited entries using each message body's optional id field. An authenticated user could store id-less messages in a parent cycle and trigger a non-terminating walk that blocked the async event loop, grew memory until termination, and remained persistent across process restarts. This issue is fixed in version 0.11.1.","published":"2026-09-09T21:40:06.412Z","modified":"2026-09-11T03:48:43.755323408Z","cvss":{"score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"PyPI","name":"open-webui","fixedVersion":"0.11.1"}],"fix":{"url":"https://github.com/open-webui/open-webui/commit/5c79ccc9e5c9efc2bc024d8f0b9757652ece929a","label":"open-webui/open-webui@5c79ccc"},"references":[{"type":"WEB","url":"https://github.com/open-webui/open-webui/releases/tag/v0.11.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/88xxx/CVE-2026-88002.json"},{"type":"ADVISORY","url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-jqhh-cjmq-vmv6"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-88002"},{"type":"FIX","url":"https://github.com/open-webui/open-webui/commit/5c79ccc9e5c9efc2bc024d8f0b9757652ece929a"},{"type":"FIX","url":"https://github.com/open-webui/open-webui/pull/28034"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-11T03:48:43.755323408Z"}}