Mattermost DoS via Unchecked Resource Consumption in Auth'd Users (<=11.9.0)
CVE-2026-14298 Published on August 13, 2026

Denial of service via resource exhaustion in Mattermost
Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to properly limit resource consumption when processing certain user-supplied input, which allows an authenticated user to cause a denial of service. Mattermost Advisory ID: MMSA-2026-00713

Vendor Advisory NVD

Vulnerability Analysis

CVE-2026-14298 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 Data Amplification Vulnerability?

The software does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output. An example of data amplification is a "decompression bomb," a small ZIP file that can produce a large amount of data when it is decompressed.

CVE-2026-14298 has been classified to as a Data Amplification vulnerability or weakness.


Products Associated with CVE-2026-14298

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MatterMost
 

Affected Versions

Mattermost: