Go/github.com/mattermost/mattermost-server CVE-2026-2455: medium 4.3, EPSS 0.17%
Mattermost fails to canonicalize IPv4-mapped IPv6 addresses before reserved IP validation
Action: Upgrade github.com/mattermost/mattermost-server to 5.3.2-0.20260129133647-5d787969c2d5 or later.
go get github.com/mattermost/mattermost-server@v5.3.2-0.20260129133647-5d787969c2d5go get github.com/mattermost/mattermost-server@v10.11.11go get github.com/mattermost/mattermost-server@v11.2.3go get github.com/mattermost/mattermost-server@v11.3.1Affected
| introduced | fixed | last affected |
|---|---|---|
| 0 | 5.3.2-0.20260129133647-5d787969c2d5 | - |
| 10.11.0-rc1 | 10.11.11 | - |
| 11.2.0-rc1 | 11.2.3 | - |
| 11.3.0-rc1 | 11.3.1 | - |
Fixed versions
| 5.3.2-0.20260129133647-5d787969c2d5 | 10.11.11 | 11.2.3 | 11.3.1 |
Sources
- osv: GHSA-gqv7-j2j8-qmwq#Go/github.com/mattermost/mattermost-server
- https://nvd.nist.gov/vuln/detail/CVE-2026-2455
- https://github.com/mattermost/mattermost/commit/5d787969c2d5ab591a9dcd61b0810475eed7a646
- https://github.com/mattermost/mattermost
- https://mattermost.com/security-updates
CVE-2026-2455 · published · modified · JSON