tocsin

CVE-2026-4915

6 advisories.

Go/github.com/mattermost/mattermost-server CVE-2026-4915: medium 6.5

Mattermost doesn't filter nil elements from outgoing webhook attachment payloads before processing

Action: Upgrade github.com/mattermost/mattermost-server to 10.11.15 or later.

go get github.com/mattermost/mattermost-server@v11.6.1
go get github.com/mattermost/mattermost-server@v11.5.4
go get github.com/mattermost/mattermost-server@v11.4.5
go get github.com/mattermost/mattermost-server@v10.11.15

Affected

introducedfixedlast affected
11.6.011.6.1-
11.5.011.5.4-
11.4.011.4.5-
10.11.010.11.15-

Fixed versions

11.6.111.5.411.4.510.11.15

Sources

CVE-2026-4915 · published · modified · JSON

Go/github.com/mattermost/mattermost/server/v8 CVE-2026-4915: medium 6.5

Mattermost doesn't filter nil elements from outgoing webhook attachment payloads before processing

Action: Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20260407102538-faa7d75b4ea0 or later.

go get github.com/mattermost/mattermost/server/v8@v8.0.0-20260407102538-faa7d75b4ea0

Affected

introducedfixedlast affected
08.0.0-20260407102538-faa7d75b4ea0-

Fixed versions

8.0.0-20260407102538-faa7d75b4ea0

Sources

CVE-2026-4915 · published · modified · JSON

Go/github.com/mattermost/mattermost-server CVE-2026-4915: unknown

Mattermost doesn't filter nil elements from outgoing webhook attachment payloads before processing in github.com/mattermost/mattermost-server

Action: Upgrade github.com/mattermost/mattermost-server to 10.11.15+incompatible or later.

go get github.com/mattermost/mattermost-server@v10.11.15+incompatible
go get github.com/mattermost/mattermost-server@v11.4.5+incompatible
go get github.com/mattermost/mattermost-server@v11.5.4+incompatible
go get github.com/mattermost/mattermost-server@v11.6.1+incompatible

Affected

introducedfixedlast affected
10.11.0+incompatible10.11.15+incompatible-
11.4.0+incompatible11.4.5+incompatible-
11.5.0+incompatible11.5.4+incompatible-
11.6.0+incompatible11.6.1+incompatible-

Fixed versions

10.11.15+incompatible11.4.5+incompatible11.5.4+incompatible11.6.1+incompatible

Sources

CVE-2026-4915 · published · modified · JSON

Go/github.com/mattermost/mattermost-server/v5 CVE-2026-4915: unknown

Mattermost doesn't filter nil elements from outgoing webhook attachment payloads before processing 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-2026-4915 · published · modified · JSON

Go/github.com/mattermost/mattermost-server/v6 CVE-2026-4915: unknown

Mattermost doesn't filter nil elements from outgoing webhook attachment payloads before processing 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-2026-4915 · published · modified · JSON

Go/github.com/mattermost/mattermost/server/v8 CVE-2026-4915: unknown

Mattermost doesn't filter nil elements from outgoing webhook attachment payloads before processing in github.com/mattermost/mattermost-server

Action: Upgrade github.com/mattermost/mattermost/server/v8 to 8.0.0-20260407102538-faa7d75b4ea0 or later.

go get github.com/mattermost/mattermost/server/v8@v8.0.0-20260407102538-faa7d75b4ea0

Affected

introducedfixedlast affected
08.0.0-20260407102538-faa7d75b4ea0-

Fixed versions

8.0.0-20260407102538-faa7d75b4ea0

Sources

CVE-2026-4915 · published · modified · JSON