Mattermost allows demoted guests to change group names

Description

References

• nvd.nist.gov/vuln/detail/CVE-2023-50333 · ADVISORY
• mattermost/mattermost commit 61dd452 · WEB
• mattermost/mattermost · PACKAGE
• mattermost.com/security-updates · WEB
• GitHub Advisory GHSA-9w97-9rqx-8v4j · ADVISORY

More vulnerabilities in github.com/mattermost/mattermost-server

• CVE-2026-8823LOW 3.8Mattermost versions 11.7.x <= 11.7.0, 10.11.x <= 10.11.17 fail to validate bot targets when demoting users to guests which allows a lower-pr…
• CVE-2026-9162MEDIUM 4.3Mattermost 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 invalidate cached authentication state…
• CVE-2026-8074LOW 3.8Mattermost versions 11.7.x <= 11.7.0, 10.11.x <= 10.11.17 fail to enforce bot-specific permission checks on the user active status endpoint,…
• CVE-2026-6673MEDIUM 6.4Mattermost 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 authenticate Atlassian Connect install…
• CVE-2026-6062MEDIUM 6.4Mattermost 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 validate channel ownership of an exist…