GitHub Advisoryadvisory · Go

GHSA-mxxh-fmjq-j6x4 Mattermost doesn't validate whether users were correctly owned by the correct Connected Workspace

LOW Published 2026-04-17 Modified 2026-04-28 Official page ↗
Aliases
CVE-2026-27769
Ecosystem
Go
Packages
github.com/mattermost/mattermost-server
Severity
Low
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N
Weaknesses
CWE-862
Reviewed
2026-04-28

Affected packages

• Go github.com/mattermost/mattermost-server: >= 8.0.0-20250721062209-4952acea88ce, < 8.0.0-20260316060126-bc1a2b34b1f9 → fixed in 8.0.0-20260316060126-bc1a2b34b1f9

Description

Mattermost versions 10.11.x <= 10.11.12 fail to validate whether users were correctly owned by the correct Connected Workspace which allows a malicious remote server connected using the Conntexted Workspaces feature to change the displayed status of local users via the Connected Workspaces API. Mattermost Advisory ID: MMSA-2026-00603.

Related

Alias · CVE (1)

  • CVE-2026-27769 Mattermost versions 10.11.x <= 10.11.12 fail to validate whether users were correctly owned by the correct Connected Workspace which allows… vulnerability

Weakness · CWE (1)

  • CWE-862 Missing Authorization weakness

References