Mattermost <=11.10.1: CSRF request body DoS via plugins
CVE-2026-96260 Published on September 22, 2026

Mattermost server missing request body size limit on plugin routes allows denial of service by an authenticated user
Mattermost versions 11.9.x <= 11.9.1, 11.8.x <= 11.8.5, 11.7.x <= 11.7.10, 11.10.x <= 11.10.1 fail to enforce a request body size limit during CSRF validation of plugin requests which allows an authenticated user to exhaust server memory and cause a denial of service via a large request body sent to a plugin endpoint.. Mattermost Advisory ID: MMSA-2026-00775

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-96260 is exploitable with network access, and requires small amount of user privileges. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
LOW
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
NONE
Integrity Impact:
NONE
Availability Impact:
HIGH

Weakness Type

What is a Stack Exhaustion Vulnerability?

The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.

CVE-2026-96260 has been classified to as a Stack Exhaustion vulnerability or weakness.


Products Associated with CVE-2026-96260

Want to know whenever a new CVE is published for MatterMost? stack.watch will email you.

MatterMost
 

Affected Versions

Mattermost: