CVE-2025-0503 Leaked User IDs and Metadata of Deleted DMs
Attackers can infer user IDs and metadata from deleted direct messages in Mattermost if DMs were manually marked as deleted in the database.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-0503?
CVE-2025-0503 is a low-severity vulnerability in Mattermost Mattermost Server, published on 14 Feb 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Mattermost versions 9.11.x <= 9.11.6 fail to filter out DMs from the deleted channels endpoint which allows an attacker to infer user IDs and other metadata from deleted DMs if someone had manually marked DMs as deleted in the database.
Weakness: CWE-754
Which versions are affected by CVE-2025-0503?
It affects 1 product.
Products include Mattermost Mattermost Server.
How do I fix CVE-2025-0503?
No fix has been published for CVE-2025-0503 yet. Limit exposure of the affected software until one is available.
Is CVE-2025-0503 being exploited?
There is no known exploitation of CVE-2025-0503 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 GHSA-cc72-wc5x-7wmj.