CVE-2026-75587 Plaintext pre-auth secret exposure via Desktop App diagnostics report
Local attackers can obtain plaintext pre-auth secrets by inspecting unredacted diagnostics reports in the Mattermost Desktop App.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-75587?
CVE-2026-75587 is a low-severity vulnerability in Mattermost, published on 17 Aug 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
Mattermost Desktop App versions <=6.2 6.2.2.0 fail to redact the pre-auth secret when generating a diagnostics report, which allows a local attacker with access to a user's diagnostics report or log files to obtain the plaintext pre-auth secret configured for a connected server via inspecting the Server Connectivity (Step-3) diagnostics output. Mattermost Advisory ID: MMSA-2026-00716
Weakness: CWE-200
Which versions are affected by CVE-2026-75587?
It affects 1 product.
Products include Mattermost Mattermost Desktop.
How do I fix CVE-2026-75587?
No fix has been published for CVE-2026-75587 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-75587 being exploited?
There is no known exploitation of CVE-2026-75587 in the wild and no public exploit code.
Other vulnerabilities in Mattermost
Sources
Also known as GHSA-jq35-5w25-hqv7.