CVE-2025-35965

Mattermost versions 10.4.x <= 10.4.2, 10.5.x <= 10.5.0, 9.11.x <= 9.11.10 fail to validate the uniqueness and quantity of task actions within the UpdateRunTaskActions GraphQL operation, which allows an attacker to create task items containing an excessive number of actions triggered by specific posts, overloading the server and leading to a denial-of-service (DoS) condition.

The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap. Typical impact: resource exhaustion leading to denial of service.

CVE-2025-35965 has a CVSS score of 6.5 (Medium). The vector is network-reachable, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (8.0.0-20250218121836-2b5275d87136, 1.41.0); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2025-35965? CVE-2025-35965 is a medium-severity allocation of resources without limits or throttling vulnerability in github.com/mattermost/mattermost/server/v8 (go), affecting versions < 8.0.0-20250218121836-2b5275d87136. It is fixed in 8.0.0-20250218121836-2b5275d87136, 1.41.0. The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap.
2. How severe is CVE-2025-35965? CVE-2025-35965 has a CVSS score of 6.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which packages are affected by CVE-2025-35965?
   • github.com/mattermost/mattermost/server/v8 (go) (versions < 8.0.0-20250218121836-2b5275d87136)
   • github.com/mattermost/mattermost-plugin-playbooks (go) (versions >= 2.0.0, < 2.1.1)
4. Is there a fix for CVE-2025-35965? Yes. CVE-2025-35965 is fixed in 8.0.0-20250218121836-2b5275d87136, 1.41.0. Upgrade to this version or later.
5. Is CVE-2025-35965 exploitable, and should I be worried? Whether CVE-2025-35965 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2025-35965 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2025-35965?
   • Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20250218121836-2b5275d87136 or later
   • Upgrade github.com/mattermost/mattermost-plugin-playbooks to 1.41.0 or later