Vulnerability Details CVE-2026-5308
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to enforce request body size limits on plugin HTTP endpoints which allows an attacker to cause a denial of service via crafted oversized HTTP requests.. Mattermost Advisory ID: MMSA-2026-00646
Exploit prediction scoring system (EPSS) score
EPSS Score 0.001
EPSS Ranking 16.2%
CVSS Severity
CVSS v3 Score 4.9
References
Products affected by CVE-2026-5308
-
cpe:2.3:a:mattermost:mattermost_server:10.11.0
-
cpe:2.3:a:mattermost:mattermost_server:10.11.1
-
cpe:2.3:a:mattermost:mattermost_server:10.11.10
-
cpe:2.3:a:mattermost:mattermost_server:10.11.11
-
cpe:2.3:a:mattermost:mattermost_server:10.11.12
-
cpe:2.3:a:mattermost:mattermost_server:10.11.13
-
cpe:2.3:a:mattermost:mattermost_server:10.11.14
-
cpe:2.3:a:mattermost:mattermost_server:10.11.2
-
cpe:2.3:a:mattermost:mattermost_server:10.11.3
-
cpe:2.3:a:mattermost:mattermost_server:10.11.4
-
cpe:2.3:a:mattermost:mattermost_server:10.11.5
-
cpe:2.3:a:mattermost:mattermost_server:10.11.6
-
cpe:2.3:a:mattermost:mattermost_server:10.11.7
-
cpe:2.3:a:mattermost:mattermost_server:10.11.8
-
cpe:2.3:a:mattermost:mattermost_server:10.11.9
-
cpe:2.3:a:mattermost:mattermost_server:11.4.0
-
cpe:2.3:a:mattermost:mattermost_server:11.4.1
-
cpe:2.3:a:mattermost:mattermost_server:11.4.2
-
cpe:2.3:a:mattermost:mattermost_server:11.4.3
-
cpe:2.3:a:mattermost:mattermost_server:11.4.4
-
cpe:2.3:a:mattermost:mattermost_server:11.5.0
-
cpe:2.3:a:mattermost:mattermost_server:11.5.1
-
cpe:2.3:a:mattermost:mattermost_server:11.5.2
-
cpe:2.3:a:mattermost:mattermost_server:11.5.3
-
cpe:2.3:a:mattermost:mattermost_server:11.6.0