CVE-2026-54020: open-webui

Vulnerability summary

CVE-2026-54020 is a medium (CVSS 6.3) vulnerability in open-webui. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 15.6% of scored vulnerabilities.

Timeline

1. 04-08-2026
   PublishedVulnerability first disclosed.
2. 05-08-2026
   Last modifiedVulnerability information updated.

Description

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. Prior to 0.11.0, Open WebUI resolved a hostname during URL validation and rejected private, loopback, and link-local addresses, but the HTTP clients resolved the hostname again at connection time. An authenticated attacker who controlled authoritative DNS for a submitted hostname could answer with a public address during validation and an internal one during connection, reaching cloud metadata, loopback admin APIs, or internal services through URL ingest, chat image_url fetches, image editing, or OAuth profile-picture fetches, with most paths returning the response to the attacker and the OAuth path forwarding the OAuth access token. This issue is fixed in 0.11.0.

• CWE-367Time-of-check Time-of-use (TOCTOU) Race ConditionThe product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check.
• CWE-918Server-Side Request Forgery (SSRF)The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.