Headline
GHSA-ff85-qw3h-g9vp: Mattermost allows an attacker to edit arbitrary posts via a crafted MSTeams plugin OAuth redirect URL
Mattermost versions 10.11.x <= 10.11.3, 10.5.x <= 10.5.11, 10.12.x <= 10.12.0 fail to validate the relationship between the post being updated and the MSTeams plugin OAuth flow which allows an attacker to edit arbitrary posts via a crafted MSTeams plugin OAuth redirect URL.
- GitHub Advisory Database
- GitHub Reviewed
- CVE-2025-55073
Mattermost allows an attacker to edit arbitrary posts via a crafted MSTeams plugin OAuth redirect URL
Moderate severity GitHub Reviewed Published Nov 14, 2025 to the GitHub Advisory Database • Updated Nov 17, 2025
Package
gomod github.com/mattermost/mattermost-server (Go)
Affected versions
>= 10.11.0, < 10.11.4
>= 10.5.0, < 10.5.12
>= 10.12.0, < 10.12.1
Patched versions
10.11.4
10.5.12
10.12.1
gomod github.com/mattermost/mattermost/server/v8 (Go)
< 8.0.0-20250929212932-a41db04d2746
8.0.0-20250929212932-a41db04d2746
Description
Published to the GitHub Advisory Database
Nov 14, 2025
Last updated
Nov 17, 2025