Denial of Service Vulnerability in Open WebUI by Open WebUI
CVE-2026-109299

7.1HIGH

Key Information:

Vendor

Open-webui

Status
Open-webui
Vendor
CVE Published:
12 October 2026

What is CVE-2026-109299?

Open WebUI versions 0.9.0 through 0.11.4 are susceptible to a denial of service vulnerability that can be exploited by authenticated users with automation permissions. By submitting unsatisfiable recurrence rules, such as those including invalid dates, attackers can overwhelm the system and block the shared event loop, resulting in significant service interruption. This vulnerability highlights the need for stringent validation of user inputs to enhance the security and stability of the application.

Affected Version(s)

open-webui 0.9.0 < 0.11.4

open-webui 0.11.4

References

https://github.com/open-webui/open-webui/security/advisor...
vendor-advisory
https://github.com/open-webui/open-webui/commit/5fb869db2...
patch
https://www.vulncheck.com/advisories/open-webui-0.9.0-bef...
third-party-advisory

CVSS V4

Score:
7.1
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Classic298
.