{"id":"CVE-2026-45667","aliases":["GHSA-m69w-p7m4-585j","PYSEC-2026-2747"],"title":"Open WebUI: Unauthenticated endpoint can trigger embedding generation (cost/DoS)","summary":"Open WebUI: Unauthenticated endpoint can trigger embedding generation (cost/DoS)","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L","vendor":"open-webui","product":"open-webui","ecosystem":"pip","affected":["open-webui < 0.8.0"],"patched":["open-webui 0.8.0"],"published":"2026-05-14","updated":"2026-07-13","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/GHSA-m69w-p7m4-585j","references":[{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-m69w-p7m4-585j"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45667"},{"url":"https://github.com/open-webui/open-webui/commit/e5035ea31e179977e805a7032c979ff59a71860a"},{"url":"https://github.com/open-webui/open-webui"},{"url":"https://github.com/open-webui/open-webui/releases/tag/v0.8.0"}],"tags":["osv","pip"],"epss":0.00341,"epssPercentile":0.27656,"ingestedAt":"2026-07-13T18:58:00.363Z","slug":"CVE-2026-45667","body":"## Overview\n\n### 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.\n\n## Affected packages\n\n- `open-webui < 0.8.0`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `open-webui 0.8.0`","depth":"sunlit","depthScore":36,"depthScoreParts":{"impact":35.8,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}