# CVE-2026-109297: Open WebUI automation recurrence-rule denial of service

Source: https://junglewise.ai/threats/cve-2026-109297-open-webui-0-11-0-before-0-11-4-contains-a-denial-of-service  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-12. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-109297 · Severity: medium · CVSS 6.5 · Published 2026-10-12

Open WebUI is a web interface for managing AI models and automations. A denial-of-service vulnerability in versions 0.11.0 through 0.11.3 allows users with automation creation permissions to submit specially crafted recurrence rules that freeze the entire system for minutes at a time, preventing all other users from accessing the application.

Technologies: [Open WebUI](https://junglewise.ai/threats/technologies/open-webui-open-webui). Vendors: [Open WebUI](https://junglewise.ai/threats/vendors/open-webui).

## Quick answers

**Is CVE-2026-109297 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-109297 being exploited in the wild.

**How severe is CVE-2026-109297?** Medium severity, with a CVSS score of 6.5, published 12 October 2026.

**Which products and versions are affected?** Open WebUI 0.11.0 through 0.11.3.

**Is there a fix for CVE-2026-109297?** Yes: fixed in 0.11.4. Until then: Restrict the USER_PERMISSIONS_FEATURES_AUTOMATIONS setting to administrators only, which is the default. Ensure UVICORN_WORKERS is set to more than 1 to allow other workers to remain responsive during validation operations. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-109297 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-109297?** Check whether you run Open WebUI at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in 0.11.4

Restrict the USER_PERMISSIONS_FEATURES_AUTOMATIONS setting to administrators only, which is the default. Ensure UVICORN_WORKERS is set to more than 1 to allow other workers to remain responsive during validation operations.

## Technical details

The recurrence-rule validator in backend/open_webui/utils/automations.py parses rules differently than the underlying calendar library, allowing attackers to submit rules that appear benign to the validator but expand to per-second schedules when executed. Validation and scheduler polling synchronously walk every occurrence from the rule's start date to present on the shared event loop without timeout, consuming CPU for minutes and blocking all other operations. Authentication and automation creation permissions are required; this is available to non-administrators only when the automations feature is explicitly granted.

## Affected products

- Open WebUI Open WebUI 0.11.0 through 0.11.3

## Timeline

- 2026-09-27: disclosed
- 2026-10-12: advisory
- 2026-10-12: patched

## References

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

## Related threats

- [Open WebUI stored cross-site scripting in Markdown renderer](https://junglewise.ai/threats/cve-2026-109300-open-webui-from-0-6-31-before-0-11-4-contains-a-stored-cross)
- [Open WebUI denial of service in recurrence rule validation](https://junglewise.ai/threats/cve-2026-109299-open-webui-from-0-9-0-before-0-11-4-contains-a-denial-of-service)
- [Open WebUI regex denial of service in file search tools](https://junglewise.ai/threats/cve-2026-109298-open-webui-0-11-0-before-0-11-4-compiles-user-chosen-grep)
- [Open WebUI missing authorization in model provider routes](https://junglewise.ai/threats/cve-2026-109296-open-webui-before-0-11-4-contains-a-missing-authorization)
- [Open WebUI regular expression denial of service in file search](https://junglewise.ai/threats/cve-2026-109295-open-webui-from-0-11-0-before-0-11-4-contains-a-regular)