VULNERABILITY INTELLIGENCE

CVE-2026-5139

CVSS score5.4 MEDIUM
EPSS probability0.29%
CISA KEVNot currently listed
Published2026-06-22
Last modified2026-06-23
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L

Description

Mattermost versions 11.7.x <= 11.7.0, 11.6.x <= 11.6.2, 11.5.x <= 11.5.5, 10.11.x <= 10.11.17 fail to enforce administrator authorization on the {{setDefaultInstance}} call within the {{/gitlab connect}} command handler, which allows any authenticated user to overwrite the global default GitLab instance configuration via the {{/gitlab connect <instance-name>}} slash command.. Mattermost Advisory ID: MMSA-2026-00644

Weakness classification

  • CWE-862: Missing Authorization

Primary references