{"id":"CVE-2026-45667","aliases":["GHSA-m69w-p7m4-585j","PYSEC-2026-2747"],"url":"https://o3.security/vulnerability/CVE-2026-45667","summary":"Open WebUI: Unauthenticated endpoint can trigger embedding generation (cost/DoS)","details":"### Summary\nGET `/api/v1/memories/ef` is accessible without authentication and executes `request.app.state.EMBEDDING_FUNCTION(...)`. This allows any unauthenticated caller to trigger embedding generation which can lead to direct cost exposure if a paid provider is used.\nCode reference: `backend/open_webui/routers/memories.py` (@router.get(\"/ef\") -> calls `request.app.state.EMBEDDING_FUNCTION(\"hello world\"))`.\n\n\n### Details\nGET `/api/v1/memories/ef` is reachable without authentication and triggers request.app.state.EMBEDDING_FUNCTION(\"hello world\"). This crosses an intended security boundary by allowing unauthenticated users to invoke potentially expensive embedding computation and/or paid upstream embedding APIs.\n\n### PoC\n1. Start Open WebUI in default configuration (no special env hardening; default ENABLE_MEMORIES is true).\n2. From an unauthenticated client (no cookies/Authorization header), call:\n      curl -i http://\\<host\\>:\\<port\\>/api/v1/memories/ef\n   3. Observe the server performs embedding generation and returns a response like:\n   - HTTP 200 with JSON containing the result.\n\nHow it can be abused / attacker actions:\n\n- Send repeated requests to `/api/v1/memories/ef` to:\n  - consume CPU/GPU resources (DoS)\n  - generate sustained outbound usage to embedding providers if configured (cost + rate-limit exhaustion)\n  - degrade latency/availability for legitimate users\n \n### Impact\nIf embeddings are configured to use paid/remote providers (OpenAI/Azure/etc), an attacker can generate unlimited requests and incur charges.\n\n## Resolution\n\nFixed in commit [e5035ea31](https://github.com/open-webui/open-webui/commit/e5035ea31e179977e805a7032c979ff59a71860a), first released in **v0.8.0** (Feb 2026). The `/api/v1/memories/ef` route was removed entirely. It was a diagnostic/debug-style endpoint that hard-coded `\"hello world\"` through the embedding function without any authentication dependency; there was no legitimate caller that depended on it, so deletion was the cleaner fix than retrofitting auth. Users on `>= 0.8.0` are not affected.","published":"2026-05-15T21:41:43.155Z","modified":"2026-08-12T03:51:20.967814996Z","cvss":{"score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L"},"epss":{"score":0.00341,"percentile":0.26665,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"open-webui","fixedVersion":"0.8.0"}],"fix":{"url":"https://github.com/open-webui/open-webui/commit/e5035ea31e179977e805a7032c979ff59a71860a","label":"open-webui/open-webui@e5035ea"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45667.json"},{"type":"ADVISORY","url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-m69w-p7m4-585j"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45667"},{"type":"WEB","url":"https://github.com/open-webui/open-webui/commit/e5035ea31e179977e805a7032c979ff59a71860a"},{"type":"PACKAGE","url":"https://github.com/open-webui/open-webui"},{"type":"WEB","url":"https://github.com/open-webui/open-webui/releases/tag/v0.8.0"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:20.967814996Z"}}