What is CVE-2026-75587?

CVE-2026-75587 is a low-severity vulnerability in Mattermost, classified under Information Disclosure. CVSS score: 3.6/10. Published 2026-08-17.

How severe is CVE-2026-75587?

Low severity. CVSS v3 base score is 3.6 out of 10.

Information disclosure in Mattermost

CVE-2026-75587

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

Vulnerability class: Information Disclosure

CVSS v3 metric

CVSS v3 base score 3.6 (Low). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N.

Affected products

Mattermost — versions 0, 6.3.0, 6.2.3.0

Weakness classification (CWE)

CWE-200 — Information Disclosure

References

responsibledisclosure@mattermost.com (vendor-advisory)

Frequently asked questions

What is CVE-2026-75587?: CVE-2026-75587 is a low-severity vulnerability in Mattermost, classified under Information Disclosure. CVSS score: 3.6/10. Published 2026-08-17.
How severe is CVE-2026-75587?: Low severity. CVSS v3 base score is 3.6 out of 10.