CVE-2026-70489 Open WebUI: Instance-wide stall via automation recurrence rules that force multi-second parsing
Attackers can cause instance-wide denial of service by submitting automation rules that trigger excessive synchronous parsing on the event loop.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-70489?
CVE-2026-70489 is a medium-severity denial of service vulnerability in Openwebui Open Webui, published on 4 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.0 until 0.11.0, automation recurrence parsing in backend/open_webui/utils/automations.py anchored minutely and hourly rules at a fixed date of 2000-01-01 and then walked forward one interval at a time to find the next run. A single FREQ=MINUTELY rule enumerates roughly a quarter-century of occurrences synchronously on the event loop that also serves scheduler, HTTP, and WebSocket traffic, and the scheduler recomputes the next run for every claimed row on each poll. This causes availability impact for every other user of the instance. This issue is fixed in 0.11.0.
Which versions are affected by CVE-2026-70489?
3 open source packages ship an affected version, including open-webui. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
open-webui PyPI | From 0.9.0 | 0.11.0 |
open-webui PyPI | From 0.9.0 | 0.11.0 |
open-webui PyPI | From 0.9.0 | 0.11.0 |
Products include Openwebui Open Webui.
How do I fix CVE-2026-70489?
Upgrade open-webui to 0.11.0 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-70489 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-70489 exists.
Other vulnerabilities in Openwebui Open Webui
- CVE-2026-44551 Open WebUI: LDAP Empty Password Authentication Bypass
- CVE-2026-56400 open-webui - Remote Code Execution via CORS Misconfiguration and Session Validation
- CVE-2024-8017 Cross-site Scripting (XSS) in open-webui/open-webui
- CVE-2026-45672 Open WebUI: Jupyter code execution works despite `ENABLE_CODE_EXECUTION=false` — feature gate bypassed
- CVE-2026-87995 Open WebUI: Same-origin XSS to account takeover via terminal port-preview iframe hardcoding allow-same-origin
Sources
Also known as GHSA-73cq-mcgh-379c, PYSEC-2026-3644.