CVE-2026-45339: Open WebUI's API key endpoint restrictions bypassed via `x-api-key` header — full message processing on restricted endpoints

May 14, 2026 (updated May 15, 2026)

Open WebUI allows admins to restrict which API endpoints an API key can access. When an API key is restricted from /api/v1/messages, requests using the Authorization: Bearer sk-... header are correctly blocked with 403. However, the same key sent via the x-api-key header bypasses the restriction entirely — the request is authenticated, the model is invoked, and a full response is returned.

References

github.com/advisories/GHSA-57q6-fvp4-pqmm
github.com/open-webui/open-webui/releases/tag/v0.9.0
github.com/open-webui/open-webui/security/advisories/GHSA-57q6-fvp4-pqmm
nvd.nist.gov/vuln/detail/CVE-2026-45339

Code Behaviors & Features

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