CVE-2026-6673
Fixed upstream EPSS <1%CVSS 6.4
Mattermost versions 11.7.x <= 11.7.0, 11.6.x <= 11.6.2, 11.5.x <= 11.5.5, 10.11.x <= 10.11.17 fail to authenticate Atlassian Connect installed callbacks, allowing a remote unauthenticated attacker to inject a rogue sharedSecret and disrupt the Jira integration via POST to /ac/installed during the pending-install window.. Mattermost Advisory ID: MMSA-2026-00654
Products: Mattermost
Fixed upstream
| Ecosystem | Package | Fixed in |
|---|---|---|
| Go | github.com/mattermost/mattermost-server | 11.7.1 |
| Go | github.com/mattermost/mattermost-server | 11.6.3 |
| Go | github.com/mattermost/mattermost-server | 11.5.6 |
| Go | github.com/mattermost/mattermost-server | 10.11.18 |
| Go | github.com/mattermost/mattermost-server | 10.11.18+incompatible |
| Go | github.com/mattermost/mattermost-server | 11.5.6+incompatible |
| Go | github.com/mattermost/mattermost-server | 11.6.3+incompatible |
| Go | github.com/mattermost/mattermost-server | 11.7.1+incompatible |