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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 in github.com/mattermost/mattermost-server

Action: Upgrade github.com/mattermost/mattermost-server to 10.11.11+incompatible or later.

go get github.com/mattermost/mattermost-server@v10.11.11+incompatible
go get github.com/mattermost/mattermost-server@v11.2.3+incompatible
go get github.com/mattermost/mattermost-server@v11.3.1+incompatible

Affected

introducedfixedlast affected
10.11.0-rc1+incompatible10.11.11+incompatible-
11.2.0-rc1+incompatible11.2.3+incompatible-
11.3.0-rc1+incompatible11.3.1+incompatible-

Fixed versions

10.11.11+incompatible11.2.3+incompatible11.3.1+incompatible

Sources

CVE-2026-2455 · published · modified · JSON