CVE-2025-55074: Channel member objects leak read status

Published Nov 18, 2025
·
Updated

Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11 fail to enforce access permissions on the Agents plugin which allows other users to determine when users had read channels via channel member objects

Other sources

Mattermost versions 10.11.x <= 10.11.3, and 10.5.x <= 10.5.11 fail to enforce access permissions on the Agents plugin which allows other users to determine when users had read channels via channel member objects.

— GitHub

Affected Software

6 affected componentsFixes available
Mattermost Mattermost<=10.11.3, <=10.5.11
go/github.com/mattermost/mattermost/server/v8<8.0.0-20250905150616-ba86dfc5876b6
8.0.0-20250905150616-ba86dfc5876b6
go/github.com/mattermost/mattermost-server>=10.5.0<10.5.12
10.5.12
go/github.com/mattermost/mattermost-server>=10.11.0<10.11.4
10.11.4
Mattermost Mattermost Server>=10.5.0<10.5.12
Mattermost Mattermost Server>=10.11.0<10.11.4

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade go/github.com/mattermost/mattermost/server/v8 to a version that resolves this vulnerability.

    Fixed in 8.0.0-20250905150616-ba86dfc5876b6
  2. Upgrade

    Upgrade go/github.com/mattermost/mattermost-server to a version that resolves this vulnerability.

    Fixed in 10.5.12
  3. Upgrade

    Upgrade go/github.com/mattermost/mattermost-server to a version that resolves this vulnerability.

    Fixed in 10.11.4
  4. Upgrade

    Upgrade Mattermost to a version that resolves this vulnerability.

    Fixed in 11.0.0
  5. Upgrade

    Upgrade Mattermost to a version that resolves this vulnerability.

    Fixed in 10.11.4
  6. Upgrade

    Upgrade Mattermost to a version that resolves this vulnerability.

    Fixed in 10.5.12

Event History

Nov 18, 2025
CVE Published
via MITRE·03:23 PM
Data Sourced
via MITRE·03:23 PM
RemedyDescriptionSeverityWeakness
Data Sourced
via NVD·04:15 PM
DescriptionSeverityAffected Software
Advisory Published
via GitHub·06:32 PM
Data Sourced
via GitHub·06:32 PM
DescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2025-55074?

CVE-2025-55074 has been classified as a medium severity vulnerability.

2

How do I fix CVE-2025-55074?

To fix CVE-2025-55074, you should update Mattermost to versions later than 10.11.3 or later than 10.5.11.

3

What does CVE-2025-55074 affect?

CVE-2025-55074 affects Mattermost versions 10.11.x up to 10.11.3 and 10.5.x up to 10.5.11.

4

What is the impact of CVE-2025-55074?

CVE-2025-55074 allows unauthorized users to access channel member objects, revealing when users had read channels.

5

Is there a workaround for CVE-2025-55074?

There are no specific workarounds for CVE-2025-55074; the recommended action is to update to secure versions.

Company

Resources

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203