PoC Index

CVE-2026-45339

MEDIUM 6.5EPSS 0.3%

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, 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. This vulnerability is fixed in 0.9.0.

CVSS v3.1
6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
CVSS v3.1
6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N
EPSS
0.31% chance of exploitation in the next 30 days, 23th percentile
Published
2026-05-15
Updated
2026-05-19

Proof-of-concept exploits (1)

References

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