Moole Vulnerability Database

Find real vulnerabilities before they ship

Medium

CVE-2026-2455

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 fail to canonicalize IPv4-mapped IPv6 addresses before reserved IP validation which allows an attacker to perform SSRF attacks against internal services via IPv4-mapped IPv6 literals (e.g., [::ffff:127.0.0.1]).. Mattermost Advisory ID: MMSA-2026-00585

VectorNETWORK

PublishedMar 16, 2026, 15:16

Published Byresponsibledisclosure@mattermost.com

Base Score

Score4.3

Affected Versions

Package (Ecosystem)IntroducedFixedLimit

github.com/mattermost/mattermost/server/v8(Go)08.0.0-20260129133647-5d787969c2d5N/A

github.com/mattermost/mattermost-server(Go)05.3.2-0.20260129133647-5d787969c2d5N/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-918

CVSS Metrics

Base Score

4.3

Vector String

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

Base SeverityMedium

Version

3.1

Attack Vector (AV)

NETWORK