Inefficient regular expression complexity in Open WebUI - #VU140748
Published: August 3, 2026
Vulnerability identifier: #VU140748
CSH Severity: Low
CVSS v4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-1333
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to inefficient regular expression complexity in grep_knowledge_files when processing a user-supplied knowledge-search pattern. A remote user can supply a crafted pattern that triggers catastrophic backtracking to cause a denial of service.
User interaction by the model is required to invoke the affected tool with the supplied literal pattern, and single-worker deployments can lose the whole instance while multi-worker deployments lose one worker per request.
Affected software
Open WebUI
Remediation
Install security update from vendor's website.
Open WebUI - update to 0.11.0