CVE-2025-11777

Mattermost versions 10.11.x = 10.11.3, 10.5.x = 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint...

Mattermost Incorrect Authorization vulnerability

Mattermost versions 10.11.x = 10.11.3, 10.5.x = 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API, which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint...

EUVD-2025-175343

Mattermost versions 10.11.x = 10.11.3, 10.5.x = 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint...

GHSA-MQCJ-8C2G-H97Q Mattermost Incorrect Authorization vulnerability

Mattermost versions 10.11.x = 10.11.3, 10.5.x = 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API, which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint...

CVE-2025-11777

Mattermost versions 10.11.x = 10.11.3, 10.5.x = 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint...

5 Exposure Management Best Practices for Your Team

Let's be honest: the traditional approach to vulnerability management is broken. Your team is likely drowning in a sea of alerts, staring at scan reports thousands of lines long, and struggling to figure out what to fix first. This constant state of reactive fire-fighting is exhausting and, worse...

CVE-2025-11777 Cross-team channel membership access

Mattermost versions 10.11.x = 10.11.3, 10.5.x = 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint...

CVE-2025-11777 Cross-team channel membership access

Mattermost versions 10.11.x = 10.11.3, 10.5.x = 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint...

CVE-2025-11777 Cross-team channel membership access

Mattermost versions 10.11.x = 10.11.3, 10.5.x = 10.5.11 fail to properly validate team membership permissions in the Add Channel Member API which allows users from one team to access user metadata and channel membership information from other teams via the API endpoint...

CVE-2025-11777

Affected products/versions: Mattermost Server 10.5.x (<= 10.5.11) and 10.11.x (

PT-2025-46871

Name of the Vulnerable Software and Affected Versions Mattermost versions 10.5.0 through 10.5.11 Mattermost versions 10.11.0 through 10.11.3 Description The software does not properly validate team membership permissions in the Add Channel Member API. This allows users from one team to access use...

Beyond CVSS: Critical CVE Vulnerabilities Analysis

Attackers don't care about your CVSS scores. They care about finding a path into your network. That path might not be a single, glaring "critical" vulnerability. Often, it’s a chain of lower-severity weaknesses on overlooked assets that, when combined, give them the keys to the kingdom. This is w...

CISA and UK NCSC Release Joint Guidance for Securing OT Systems

CISA, in collaboration with the Federal Bureau of Investigation, the United Kingdom’s National Cyber Security Centre, and other international partners has released new joint cybersecurity guidance: Creating and Maintaining a Definitive View of Your Operational Technology OT Architecture. Building...

postMessaged and Compromised

At Microsoft, securing the ecosystem means more than just fixing bugs—it means proactively hunting for variant classes, identifying systemic weaknesses, and working across teams to protect customers before attackers ever get the chance. This blog highlights one such effort: a deep dive into the...

Rapid7 Podcast Explores Hybrid-First Workplace Learnings

As the world continues to navigate the post-pandemic shift in work environments, Rapid7 is operating on a hybrid-first approach that balances flexibility and productivity with collaboration and optimizing for customer success. In the spirit of cross-collaboration, the People Development and...

Threat Source newsletter (Jan. 19, 2023): Talent retention and institutional knowledge

Welcome to this weeks edition of the Threat Source newsletter. Talent retention and institutional knowledge go hand in hand. Both are critical to ensuring the security of your network environment. To that end, I want to talk briefly about why talent retention isnt just about money. So I am going ...

Dradis v2.9 - Information Sharing For Security Assessments

Dradis is an open source framework to enable effective information sharing, specially during security assessments. It’s a tool specifically to help in the process of penetration testing. Penetration testing is about information: 1. Information discovery 2. Exploit useful information 3. Report the...