CVE-2026-109297

Open WebUI 0.11.0 before 0.11.4 contains a denial of service vulnerability in the automation recurrence-rule validator, whose sub-daily frequency guard parses rule text more strictly than the calendar library that executes it. Users permitted to create automations can submit whitespace-folded rules (or, in 0.11.0, lowercase frequencies or omitted RRULE prefixes) that expand per-second synchronously, blocking the shared event loop for minutes per request and on every scheduler poll.

• https://github.com/open-webui/open-webui/security/advisories/GHSA-whgc-vpjx-m3qh
• https://www.vulncheck.com/advisories/open-webui-0.11.0-before-0.11.4-denial-of-service-via-automation-recurrence-rules
• https://github.com/open-webui/open-webui/security/advisories/GHSA-whgc-vpjx-m3qh