tocsin

CVE-2026-2458

6 advisories.

Go/github.com/mattermost/mattermost/server/v8 CVE-2026-2458: medium 4.3, EPSS 0.17%

Mattermost allows a removed team member to enumerate all public channels within a private team

Action: Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20260113182106-a18b80ba4c32 or later.

go get github.com/mattermost/mattermost/server/v8@v8.0.0-20260113182106-a18b80ba4c32

Affected

introducedfixedlast affected
08.0.0-20260113182106-a18b80ba4c32-

Fixed versions

8.0.0-20260113182106-a18b80ba4c32

Sources

CVE-2026-2458 · published · modified · JSON

Go/github.com/mattermost/mattermost-server CVE-2026-2458: medium 4.3, EPSS 0.17%

Mattermost allows a removed team member to enumerate all public channels within a private team

Action: Upgrade github.com/mattermost/mattermost-server to 5.3.2-0.20260113182106-a18b80ba4c32 or later.

go get github.com/mattermost/mattermost-server@v5.3.2-0.20260113182106-a18b80ba4c32
go get github.com/mattermost/mattermost-server@v10.11.11
go get github.com/mattermost/mattermost-server@v11.2.3
go get github.com/mattermost/mattermost-server@v11.3.1

Affected

introducedfixedlast affected
05.3.2-0.20260113182106-a18b80ba4c32-
10.11.0-rc110.11.11-
11.2.0-rc111.2.3-
11.3.0-rc111.3.1-

Fixed versions

5.3.2-0.20260113182106-a18b80ba4c3210.11.1111.2.311.3.1

Sources

CVE-2026-2458 · published · modified · JSON

Go/github.com/mattermost/mattermost-server CVE-2026-2458: unknown, EPSS 0.17%

Mattermost allows a removed team member to enumerate all public channels within a private team 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-2026-2458 · published · modified · JSON

Go/github.com/mattermost/mattermost-server/v5 CVE-2026-2458: unknown, EPSS 0.17%

Mattermost allows a removed team member to enumerate all public channels within a private team in github.com/mattermost/mattermost-server

Action: No fix published. Pin and monitor.

Affected

introducedfixedlast affected
0--

Fixed versions

No fixed version in the source.

Sources

CVE-2026-2458 · published · modified · JSON

Go/github.com/mattermost/mattermost-server/v6 CVE-2026-2458: unknown, EPSS 0.17%

Mattermost allows a removed team member to enumerate all public channels within a private team in github.com/mattermost/mattermost-server

Action: No fix published. Pin and monitor.

Affected

introducedfixedlast affected
0--

Fixed versions

No fixed version in the source.

Sources

CVE-2026-2458 · published · modified · JSON

Go/github.com/mattermost/mattermost/server/v8 CVE-2026-2458: unknown, EPSS 0.17%

Mattermost allows a removed team member to enumerate all public channels within a private team in github.com/mattermost/mattermost-server

Action: Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20260113182106-a18b80ba4c32 or later.

go get github.com/mattermost/mattermost/server/v8@v8.0.0-20260113182106-a18b80ba4c32

Affected

introducedfixedlast affected
08.0.0-20260113182106-a18b80ba4c32-

Fixed versions

8.0.0-20260113182106-a18b80ba4c32

Sources

CVE-2026-2458 · published · modified · JSON