4.3Medium

Openwebui Open Webui

CVE-2026-87012

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.0 until 0.11.1, backend/open_webui/models/calendar.py stored the calendar event meta.alert_minutes value without type validation and the shared upcoming-event scheduler compared that value numerically. An authenticated user with the calendar permission could store a non-numeric alert_minutes value that raised an exception and aborted the instance-wide alert pass, suppressing all users' reminders while the event remained in the lookahead window. This issue is fixed in version 0.11.1.

What this means for your business

  • It affects Openwebui Open Webui. It matters if your company, or a supplier that handles your data, runs it.
  • Code showing how to exploit it has been published, but real attacks have not been confirmed.
  • An attacker can use it remotely, over a network, with an ordinary user login, and without anyone at your company clicking anything.

What to do

  1. 1Check whether your company or your suppliers run Openwebui Open Webui, and which version. The affected versions are listed further down this page.
  2. 2If you do, apply the vendor's fix. A patch or vendor advisory has been published.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Scoring

CVSS
4.3 (v3.1)
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Weakness
CWE-754
Assigned by
security-advisories@github.com

Dates

Published
2026-09-09
Last modified
2026-09-15
Sources
NVD

Affected products

  • Openwebui Open Webui0.9.0 - 0.11.1

As listed in the NVD configuration data. Not a statement about your estate.

References