CVE-2026-4635
Fixed in a distro release EPSS <1%CVSS 6.5
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 archive the channel before removing persistent notifications which allows authenticated user to crash the server via timing the creation of persistent notification message between the server deleting existing persistent notifications and archiving the channel.. Mattermost Advisory ID: MMSA-2026-00637
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 |