GitHub Advisoryadvisory · Go

GHSA-gg42-mwr6-p82c Mattermost Server has intermittent Authorization bypass for resource-owners

HIGH Published 2022-05-24 Modified 2026-01-12 Official page ↗
Aliases
CVE-2017-18894
Ecosystem
Go
Packages
github.com/mattermost/mattermost-server
Severity
High
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Weaknesses
CWE-639, CWE-732
Reviewed
2026-01-12

Affected packages

• Go github.com/mattermost/mattermost-server: < 4.0.5 → fixed in 4.0.5 • Go github.com/mattermost/mattermost-server: >= 4.1.0, < 4.1.1 → fixed in 4.1.1 • Go github.com/mattermost/mattermost-server: >= 4.2.0-rc1, < 4.2.0 → fixed in 4.2.0

Description

An issue was discovered in Mattermost Server before 4.2.0, 4.1.1, and 4.0.5, when used as an OAuth 2.0 service provider. Resource-owner authorization can be intermittently bypassed, allowing account takeover.

Related

Alias · CVE (1)

  • CVE-2017-18894 An issue was discovered in Mattermost Server before 4.2.0, 4.1.1, and 4.0.5, when used as an OAuth 2.0 service provider. vulnerability

Weakness · CWE (2)

  • CWE-639 Authorization Bypass Through User-Controlled Key weakness
  • CWE-732 Incorrect Permission Assignment for Critical Resource weakness

References