{"items":[{"id":"NVI-00015382","kind":"vulnerability","title":"Open WebUI: ReDoS in skill-mention regexes causes whole-instance DoS on default config","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-ffpj-xv5c-p3gw","CVE-2026-59220"],"plain_summary":"GitHub lists this reviewed advisory for open-webui. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-629e1f3475e88f1fff42b1f07f1b6a93"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-07-24T16:55:58.000Z","value":"6.5 medium","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-629e1f3475e88f1fff42b1f07f1b6a93"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-629e1f3475e88f1fff42b1f07f1b6a93","url":"https://github.com/advisories/GHSA-ffpj-xv5c-p3gw","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-ffpj-xv5c-p3gw","publisher":"GitHub Advisory Database","observed_at":"2026-11-03T09:59:13.529Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-629e1f3475e88f1fff42b1f07f1b6a93"],"technology":"open-webui","known_exclusions":[],"conditions_summary":"## Summary\nTwo regexes in `backend/open_webui/utils/middleware.py` that parse `` skill-mention tags backtrack in O(n²) on input that contains ``. Both run synchronously, on the asyncio event loop, on **every** chat completion with no feature gate. Because the default deployment is a single uvicorn worker, one such input pins a CPU core inside `re` and freezes the entire instance for all users until the worker is killed. Any authenticated user can trigger it with one chat message; it also fires accidentally on benign retrieved content (a RAG chunk or tool output) containing the pattern.\n\n## Affected versions\n`>= 0.9.2, < 0.10.0`. Fixed in **v0.10.0** (there is no 0.9.7 release).\n- `SKILL_MENTION_RE` (the extract pattern) has been O(n²) since **v0.9.2**; exploitable on 0.9.2–0.9.5 with a large input (hundreds of KB).\n- **v0.9.6** added a second, far more aggressive O(n²) in the strip pattern (introduced by the \"keep label as readable text\" change), so on 0.9.6 a small input is enough to hang the instance.\n\nBoth are fixed by the same patch.\n\n## Affected component\n`backend/open_webui/utils/middleware.py` (line numbers as of v","public_affected_ranges":[">= 0.9.2, < 0.10.0"]}],"null_published_at":"2026-11-03T10:03:31.361Z","source_updated_at":"2026-07-24T16:55:58.000Z","source_disclosed_at":"2026-07-24T16:55:55.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-11-03T09:59:13.529Z"}],"next_cursor":null,"snapshot_revision":"42594"}