Moole Vulnerability Database

Find real vulnerabilities before they ship

Medium

CVE-2026-25783

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to properly validate User-Agent header tokens which allows an authenticated attacker to cause a request panic via a specially crafted User-Agent header. Mattermost Advisory ID: MMSA-2026-00586

VectorNETWORK

PublishedMar 16, 2026, 14:18

Published Byresponsibledisclosure@mattermost.com

Base Score

Score4.3

Affected Versions

Package (Ecosystem)IntroducedFixedLimit

github.com/mattermost/mattermost/server/v8(Go)08.0.0-20260129181235-1346cf529aefN/A

github.com/mattermost/mattermost-server(Go)05.3.2-0.20260129181235-1346cf529aefN/A

github.com/mattermost/mattermost-server(Go)10.11.0-rc110.11.11N/A

github.com/mattermost/mattermost-server(Go)11.2.0-rc111.2.3N/A

github.com/mattermost/mattermost-server(Go)11.3.0-rc111.3.1N/A

References

https://mattermost.com/security-updates

Weakness Type

CWE-1287

CVSS Metrics

Base Score

4.3

Vector String

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

Base SeverityMedium

Version

3.1

Attack Vector (AV)

NETWORK