CVE-2026-54021: medium-severity vulnerability in open-webui
Open WebUI: Authenticated users can target arbitrary configured Ollama backends via unguarded url_idx path parameter
Published · Updated
13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 6.3epss 0.3%
exploitation probability
0.3%top 81% of all CVEs
observed exploitation
nono source reports it
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6, several direct, index-addressed Ollama proxy routes accept a caller-supplied url_idx path parameter and use it as a raw index into the admin-configured OLLAMA_BASE_URLS list. Access control on these routes validates only whether the user may use the requested model, never which backend the request is routed to. Any authenticated user can append an arbitrary url_idx to force their request onto an Ollama backend they were never authorized to reach, including internal, higher-privilege, or explicitly admin-disabled backends. This vulnerability is fixed in 0.9.6.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Affected products
open-webui · open-webuiRelated CVEs — open-webui
In the same product, most dangerous first.
CVE-2025-64496HIGHOpen WebUI Affected by an External Model Server (Direct Connections) Code Injection via SSE EventsEPSS 7.8%CVE-2025-65958HIGHOpen WebUI vulnerable to Server-Side Request Forgery (SSRF) via Arbitrary URL Processing in /api/v1/retrieval/process/webEPSS 4.4%CVE-2026-44551CRITICALOpen WebUI: LDAP Empty Password Authentication BypassEPSS 1.6%CVE-2026-45397MEDIUMOpen WebUI: Unauthenticated RAG Configuration DisclosureEPSS 0.8%CVE-2026-45395HIGHOpen WebUI: Missing `workspace.tools` Authorization Check on Tool Update Endpoint Allows Privilege Escalation to Code ExecutionEPSS 0.7%CVE-2026-87011HIGHOpen WebUI: Unauthenticated requests can stall the server via uncached OIDC fetches in back-channel logoutEPSS 0.6%