GO-2026-5671 Mattermost doesn't validate the Host header when constructing response URLs for custom slash command in github.com/mattermost/mattermost-server

Mattermost doesn't validate the Host header when constructing response URLs for custom slash command in github.com/mattermost/mattermost-server. NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions. If this is...

CVE-2026-6333

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13 fail to validate the Host header when constructing response URLs for custom slash commands which allows an authenticated attacker to redirect slash command responses to an attacker-controlled server via a spoofed Host header.. Mattermost...