CVE-2026-2325: Improper Input Validation in MS Teams Meetings API Handler

Published May 18, 2026
·
Updated

Mattermost versions 11.5.x <= 11.5.1, 10.11.x <= 10.11.13, 11.4.x <= 11.4.3 fail to limit the size of the request body on the start meeting API endpoint, which allows an authenticated attacker to cause resource exhaustion or denial of service via a crafted oversized HTTP POST request to {{/api/v1/meetings}}.. Mattermost Advisory ID: MMSA-2026-00608

Affected Software

4 affected components
Mattermost Mattermost>=11.5.0<=11.5.1, >=10.11.0<=10.11.13, >=11.4.0<=11.4.3
Mattermost Mattermost Server>=10.11.0<10.11.14
Mattermost Mattermost Server>=11.4.0<11.4.4
Mattermost Mattermost Server>=11.5.0<11.5.2

Remediation

Information

Update Mattermost to versions 11.6.0, 11.5.2, 10.11.14, 11.4.4 or higher.

Event History

May 18, 2026
CVE Published
via MITRE·06:51 AM
Data Sourced
via MITRE·06:51 AM
RemedyDescriptionSeverityWeakness
Data Sourced
via NVD·08:16 AM
DescriptionSeverityWeaknessAffected Software

Frequently Asked Questions

1

What is the severity of CVE-2026-2325?

CVE-2026-2325 is classified as a medium severity vulnerability due to its potential for resource exhaustion and denial of service attacks.

2

How do I fix CVE-2026-2325?

To fix CVE-2026-2325, upgrade Mattermost to version 11.5.2, 10.11.14, or 11.4.4 or later, which contain the necessary patches.

3

Who is affected by CVE-2026-2325?

CVE-2026-2325 affects Mattermost versions 11.5.x up to 11.5.1, 10.11.x up to 10.11.13, and 11.4.x up to 11.4.3.

4

What is the nature of the vulnerability in CVE-2026-2325?

CVE-2026-2325 involves improper input validation that allows for unbounded request body sizes on the start meeting API endpoint.

5

Can CVE-2026-2325 be exploited remotely?

Yes, CVE-2026-2325 can be exploited by an authenticated attacker remotely, leading to possible denial of service.

Contact

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