CVE-2026-5132

Published: Sep 14, 2026Modified: Oct 7, 2026

6.5

Vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Exploitability: 2.8 / Impact: 3.6

Source: responsibledisclosure@mattermost.com (Secondary)

Description

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 limit size of unpacked SDP messages compressed with zlib, which allows attacker to deny service or crash server via sending many SDP messages that unpack to large size.. Mattermost Advisory ID: MMSA-2026-00643

Affected (4)

Products: Mattermost: Mattermost Server

Mattermost

1 product

Mattermost Server

Configuration A

4 vulnerable

Vulnerable Software	Affected Versions
Mattermost Mattermost Server	10.11.0 ≤ version < 10.11.23
Mattermost Mattermost Server	11.7.0 ≤ version < 11.7.8
Mattermost Mattermost Server	11.8.0 ≤ version < 11.8.5
Mattermost Mattermost Server	11.9.0 ≤ version < 11.9.1

Related CWEs

CWE-409

Improper Handling of Highly Compressed Data (Data Amplification)

The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output.

References (1)

https://mattermost.com/security-updates

Source: responsibledisclosure@mattermost.com

Vendor Advisory

Timeline

No history available yet.