CVE-2023-3581 WebSockets accept connections from HTTPS origin
A Man-in-the-Middle attacker can bypass origin validation to access Mattermost WebSocket APIs, potentially reading or modifying data.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-3581?
CVE-2023-3581 is a medium-severity vulnerability in Mattermost Mattermost Server, published on 17 Jul 2023. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
Mattermost fails to properly validate the origin of a websocket connection allowing a MITM attacker on Mattermost to access the websocket APIs.
Weakness: CWE-346
Which versions are affected by CVE-2023-3581?
1 open source package ship an affected version, including mattermost. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
mattermost Bitnami | From 7.8.0 | 7.8.7, 7.9.5, 7.10.3 |
Products include Mattermost Mattermost Server.
How do I fix CVE-2023-3581?
Upgrade mattermost to a fixed version for your release line: 7.8.7, 7.9.5 or 7.10.3.
Is CVE-2023-3581 being exploited?
There is no known exploitation of CVE-2023-3581 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-2023-3581, GHSA-5g2h-c436-5ppg.