CVE-2026-3473
Fixed in a distro release EPSS <1%CVSS 5.9
Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to validate file ownership and access control, which allows an authenticated user to access and download files belonging to other users or teams via crafted Boards API requests using valid file IDs.. Mattermost Advisory ID: MMSA-2026-00620
Products: Mattermost
Fixed upstream
| Ecosystem | Package | Fixed in |
|---|---|---|
| Go | github.com/mattermost/mattermost-server | 11.6.1 |
| Go | github.com/mattermost/mattermost-server | 11.5.4 |
| Go | github.com/mattermost/mattermost-server | 11.4.5 |
| Go | github.com/mattermost/mattermost-server | 10.11.15 |
| Go | github.com/mattermost/mattermost-server | 10.11.15+incompatible |
| Go | github.com/mattermost/mattermost-server | 11.4.5+incompatible |
| Go | github.com/mattermost/mattermost-server | 11.5.4+incompatible |
| Go | github.com/mattermost/mattermost-server | 11.6.1+incompatible |
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| openSUSE Leap 16.0 | govulncheck-vulndb | 0.0.20260723T184607-160000.1.1 |