SSRF in Open-Webui
CVE-2026-45401
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.5, the validate_url() function in backend/open_webui/retrieval/web/utils.py only validates the initial URL submitted by the caller. The HTTP clients used downstream (sync requests, async aiohttp, langchain's WebBaseLoader) follow HTTP 3xx redirects by default and do not re-validate the redirect target against the private-IP / metadata-IP block list. Any authenticated user can therefore submit a public URL that 302-redirects to an internal address (e.g. 127.0.0.1, 169.254.169.254, RFC1918) and read the internal response body via the /api/v1/retrieval/process/web endpoint, the /api/v1/images/... endpoints, the /api/chat/completions endpoint with an image_url content part, and any other route that calls these helpers. This vulnerability is fixed in 0.9.5.
Vulnerability class: SSRF (Server-Side Request Forgery)
EPSS: 0.003 (22.2th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 8.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:N.
Affected products
- Open-webui — versions < 0.9.5
- Openwebui Open_webui
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Mitigation, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-45401?
- CVE-2026-45401 is a high-severity vulnerability in Open-Webui, classified under Server-Side Request Forgery (SSRF). CVSS score: 8.5/10. Published 2026-05-15.
- How severe is CVE-2026-45401?
- High severity. CVSS v3 base score is 8.5 out of 10.
- Is CVE-2026-45401 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.