Openwebui Open Webui
CVE-2026-87015
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.6.27 until 0.11.1, backend/open_webui/utils/tools.py captured a cookie jar from the enclosing connection loop instead of binding it to each external tool callable. When multiple tool servers were attached and a session or system OAuth connection was processed last, a request to a different server configured for bearer authentication could include the calling user's Open WebUI session cookies, allowing that server's operator to reuse the session and take over the account. 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, without a login, but only after tricking someone into an action such as opening a file or a link.
What to do
- 1Check whether your company or your suppliers run Openwebui Open Webui, and which version. The affected versions are listed further down this page.
- 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
- 6.8 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N- Weakness
- CWE-201
- Assigned by
- security-advisories@github.com
Dates
- Published
- 2026-09-09
- Last modified
- 2026-09-15
- Sources
- NVD
Affected products
- Openwebui Open Webui0.6.27 - 0.11.1
As listed in the NVD configuration data. Not a statement about your estate.