Description
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.0 until 0.11.0, Open WebUI checked whether a user-supplied URL destination was globally routable by applying ipaddress.is_global to the literal IPv6 address without examining IPv4 addresses embedded in transition encodings. On a deployment with a NAT64 gateway, any verified user could wrap an internal or cloud-metadata IPv4 address in the NAT64 well-known prefix, pass the filter, and receive the internal response body through RAG URL ingestion, URL-to-markdown conversion, or web-search content retrieval. This issue is fixed in 0.11.0.
Affected products
openwebui: open webui
References4
- github.com/open-webui/open-webui/security/advisories/GHSA-8x5v-… ExploitVendor Advisory
- github.com/open-webui/open-webui/security/advisories/GHSA-8x5v-… ExploitVendor Advisory
- github.com/open-webui/open-webui/commit/1717b493d83c86afa82aa8b… Patch
- github.com/open-webui/open-webui/releases/tag/v0.11.0 Release Notes
Metrics
- CVSS 3.1
-
7.1
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:N - EPSS — exploit probability
- 0% percentile: 29 · as of 13 November 2026
- CWE
- CWE-918
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.