What’s Vulnerable › Vulnerabilities

CVE-2026-70485: Open WebUI: Any authenticated user can reach internal services and cloud metadata via NAT64-encoded URLs

• Severity: high (CVSS 7.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-08-04 · updated 2026-09-18
• Weakness: CWE-918

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

• open-webui: from 0.9.0 before 0.11.0 — fixed in 0.11.0

How to fix

Upgrade to a fixed version: open-webui 0.11.0. Check the vendor advisory for mitigations.

References

• https://github.com/open-webui/open-webui/commit/1717b493d83c86afa82aa8bc50139250852dd2f3
• https://github.com/open-webui/open-webui/releases/tag/v0.11.0
• https://github.com/open-webui/open-webui/security/advisories/GHSA-8x5v-cpv7-8jjp
• https://github.com/open-webui/open-webui/security/advisories/GHSA-8x5v-cpv7-8jjp

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