CVE-2023-27266 Disclosure of team owner email address when when accessing the teams API
Team admins can view the team owner's email address via the API, bypassing the ShowEmailAddress privacy setting.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-27266?
CVE-2023-27266 is a low-severity vulnerability in Mattermost Mattermost Server, published on 27 Feb 2023. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
Mattermost fails to honor the ShowEmailAddress setting when constructing a response to the /api/v4/users/me/teams API endpoint, allowing an attacker with team admin privileges to learn the team owner's email address in the response.
Weakness: CWE-200
Which versions are affected by CVE-2023-27266?
1 open source package ship an affected version, including mattermost. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
mattermost Bitnami | From 5.12.0 | 7.7.0 |
Products include Mattermost Mattermost Server.
How do I fix CVE-2023-27266?
Upgrade mattermost to 7.7.0 or later.
Is CVE-2023-27266 being exploited?
There is no known exploitation of CVE-2023-27266 in the wild and no public exploit code.
Other vulnerabilities in Mattermost Mattermost Server
- CVE-2025-12419 Account takeover on OAuth/OpenID-enabled servers
- CVE-2025-12421 Account Takeover via Code Exchange Endpoint
- CVE-2025-4981 Path Traversal Leading to RCE by Any Authenticated Mattermost User
- CVE-2025-20051 Arbitrary file read via block duplication in Mattermost Boards
- CVE-2025-25279 Arbitrary file read in Mattermost Boards via import & export board archive
Sources
Also known as BIT-mattermost-2023-27266, GHSA-cxwh-9cmm-77cp.