VulnerabilityAwaiting Analysis

CVE-2026-54020

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…

MEDIUM 6.3EPSS 0.21%

Does this matter?

Lower severity and a low EPSS score (0.21%). Track it; it rarely justifies an emergency change on its own.

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.

CVSS 3.1: 6.3 MEDIUMCVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
EPSS: 0.21% probability · 12th percentile
CISA KEV: Not listed
Weakness: CWE-367, CWE-918
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.