Privilege escalation in Open-Webui
CVE-2026-45675
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the LDAP and OAuth authentication flows use a TOCTOU (Time-of-Check-Time-of-Use) pattern for first-user admin role assignment. The regular signup handler (signup_handler in auths.py, line 663) was explicitly patched to prevent this race with the comment "Insert with default role first to avoid TOCTOU race", but the LDAP and OAuth code paths were never updated with the same fix. This vulnerability is fixed in 0.9.0.
Vulnerability class: Privilege Escalation
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.1 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.005 (40.8th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 41st percentile — 40.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.005 · change: +0.002
Affected products
- Open-Webui — versions < 0.9.0
- Openwebui Open Webui
Weakness classification (CWE)
References
- github.com/open-webui/open-webui/security/advisories/GHSA-h3ww-q6xx-w7x3 (Exploit, Mitigation, Vendor Advisory)
- github.com/open-webui/open-webui/pull/23626 (Issue Tracking)
- github.com/open-webui/open-webui/commit/96a0b3239b1aadb23fc359bf10849c9ba12fd6ec (Patch)
Frequently asked questions
- What is CVE-2026-45675?
- CVE-2026-45675 is a high-severity vulnerability in Open-Webui, classified under Improper Privilege Management. CVSS score: 8.1/10. Published 2026-05-15.
- How severe is CVE-2026-45675?
- High severity. CVSS v3 base score is 8.1 out of 10.