CVSS 3.1
7.1 highCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:NCVE-2026-3473
High (7.1) in mattermost mattermost server. EPSS 0.1% chance of exploitation in the next 30 days. Fixed in github.com/mattermost/mattermost-server 10.11.15, 10.11.15+incompatible, 11.4.5.
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
Severity
- EPSS
- 0.1% chance of exploitation in the next 30 days; higher than 4% of CVEs (scores of 2026-10-31)
- CWE
- CWE-639
- Published
- Modified
- Record from
- the NVD, synced
Affected
- mattermost:mattermost_server
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-7pf2-9c95-w332 | Go | github.com/mattermost/mattermost-server | >=11.6.0 <11.6.1 | 11.6.1 |
| GHSA-7pf2-9c95-w332 | Go | github.com/mattermost/mattermost-server | >=11.5.0 <11.5.4 | 11.5.4 |
| GHSA-7pf2-9c95-w332 | Go | github.com/mattermost/mattermost-server | >=11.4.0 <11.4.5 | 11.4.5 |
| GHSA-7pf2-9c95-w332 | Go | github.com/mattermost/mattermost-server | >=10.11.0 <10.11.15 | 10.11.15 |
| GO-2026-5817 | Go | github.com/mattermost/mattermost-server | >=10.11.0+incompatible <10.11.15+incompatible >=11.4.0+incompatible <11.4.5+incompatible >=11.5.0+incompatible <11.5.4+incompatible >=11.6.0+incompatible <11.6.1+incompatible | 10.11.15+incompatible, 11.4.5+incompatible, 11.5.4+incompatible, 11.6.1+incompatible |