Origin validation error in Open WebUI - #VU152710
Published: September 28, 2026
Vulnerability identifier: #VU152710
CSH Severity: High
CVSS v4: 8.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-346
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to gain full API access as the victim.
The vulnerability exists due to an origin validation error in the community stats message handler when processing cross-origin verify:chat messages. A remote attacker can send a crafted verify:chat message with a path-traversal chat ID to gain full API access as the victim.
Exploitation requires community sharing to be enabled and a signed-in victim to visit an attacker-controlled page that opens Open WebUI in a popup.
Affected software
Open WebUI
Remediation
Install security update from vendor's website.
Open WebUI - update to 0.11.4