CVE-2026-75587 PUBLISHED

Plaintext pre-auth secret exposure via Desktop App diagnostics report

Assigner: Mattermost
Reserved: 17.08.2026 Published: 17.08.2026 Updated: 17.08.2026

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

Metrics

CVSS 3.1

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N
CVSS Score: 3.6

Attack Vector	Local	Scope	Changed
Attack Complexity	Low	Confidentiality Impact	Low
Privileges Required	None	Integrity Impact	None
User Interaction	Required	Availability Impact	None

CVSS 3.1

Product Status

Vendor	Mattermost
Product	Mattermost
Versions	Default: unaffected affected from 0 to 6.2.2 (incl.) Version 6.3.0 is unaffected Version 6.2.3.0 is unaffected

Solutions

Update Mattermost Desktop App to versions 6.3.0, 6.2.3.0 or higher.

Credits

Juho Forsén finder

References

MMSA-2026-00716

Problem Types

CWE-200 Exposure of Sensitive Information to an Unauthorized Actor CWE