CVE-2026-9824

Mattermost versions 11.7.x = 11.7.2, 11.6.x = 11.6.4, 10.11.x = 10.11.19 fail to check the managesharedchannels permission in the /share-channel autocomplete handler, which allows an authenticated user without that permission to enumerate configured remote cluster connection metadata via slash...

CVE-2026-9824

Mattermost v11.7.x ≤ 11.7.2, v11.6.x ≤ 11.6.4, and v10.11.x ≤ 10.11.19 are affected by CVE-2026-9824 due to a missing check of the manage_shared_channels permission in the /share-channel autocomplete handler. This allows an authenticated user without that permission to enumerate remote cluster co...

CVE-2026-9824 Remote cluster metadata enumeration via /share-channel autocomplete

Mattermost versions 11.7.x = 11.7.2, 11.6.x = 11.6.4, 10.11.x = 10.11.19 fail to check the managesharedchannels permission in the /share-channel autocomplete handler, which allows an authenticated user without that permission to enumerate configured remote cluster connection metadata via slash...

CVE-2026-10103

Mattermost versions 11.7.x = 11.7.2, 11.6.x = 11.6.4, 10.11.x = 10.11.19 fail to verify post ownership in the shared channel inbound sync handler, which allows an authenticated remote cluster to modify or delete posts authored by local users or other remotes via crafted sync messages referencing...

CVE-2026-10103 Authenticated remote cluster can modify or delete posts it does not own in Mattermost Connected Workspaces shared channels

Mattermost versions 11.7.x = 11.7.2, 11.6.x = 11.6.4, 10.11.x = 10.11.19 fail to verify post ownership in the shared channel inbound sync handler, which allows an authenticated remote cluster to modify or delete posts authored by local users or other remotes via crafted sync messages referencing...

CVE-2026-10103

Mattermost versions affected: 11.7.x (up to 11.7.2), 11.6.x (up to 11.6.4), and 10.11.x (up to 10.11.19) have a flaw in the shared channel inbound sync handler that fails to verify post ownership. This allows an authenticated remote cluster to modify or delete posts authored by local users or oth...

GO-2026-5432 Mattermost doesn't validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation in github.com/mattermost/mattermost-server

Mattermost doesn't validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation in github.com/mattermost/mattermost-server. NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standar...

GO-2026-5256 Mattermost does not verify remote cluster channel access when processing shared channel membership removals in github.com/mattermost/mattermost-server

Mattermost does not verify remote cluster channel access when processing shared channel membership removals in github.com/mattermost/mattermost-server. NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions. If...

GHSA-XG3J-C7Q4-F9PH Canonical MicroCeph: path traversal issue in the remote-import AP

Canonical MicroCeph versions from the squid and tentacle track are vulnerable to a path traversal issue in the remote-import API. Holders of a trusted cluster mTLS certificate such as enrolled cluster members or join token can manipulate files in an imported remote cluster within the...

CVE-2026-10720

Canonical MicroCeph versions from the squid and tentacle track are vulnerable to a path traversal issue in the remote-import API. Holders of a trusted cluster mTLS certificate such as enrolled cluster members or join token can manipulate files in an imported remote cluster within the...

PT-2026-50835

Name of the Vulnerable Software and Affected Versions Canonical MicroCeph versions from the squid and tentacle track Description A path traversal issue exists in the remote-import API. Users possessing a join token or a trusted cluster mTLS certificate, such as enrolled cluster members, can...

Insertion of Sensitive Information Into Sent Data

Overview Affected versions of this package are vulnerable to Insertion of Sensitive Information Into Sent Data in the Remote Cluster PATCH API response due to insufficient sanitization of sensitive information. An attacker can access authentication tokens by sending a PATCH request to the remote...

CVE-2026-7184

Mattermost versions 11.6.x = 11.6.1, 11.5.x = 11.5.4, 10.11.x = 10.11.15 fail to sanitize the Remote Cluster API response on PATCH operations, which allows authenticated users with the managesecureconnections permission to obtain remote cluster authentication tokens via a PATCH request to the...

CVE-2026-7184

Mattermost CVE-2026-7184 affects Mattermost versions 11.6.x up to 11.6.1, 11.5.x up to 11.5.4, and 10.11.x up to 10.11.15. The issue is a failure to sanitize the Remote Cluster API response on PATCH operations, allowing authenticated users with the {{manage_secure_connections}} permission to obta...

EUVD-2026-36500

Mattermost versions 11.6.x = 11.6.1, 11.5.x = 11.5.4, 10.11.x = 10.11.15 fail to sanitize the Remote Cluster API response on PATCH operations, which allows authenticated users with the managesecureconnections permission to obtain remote cluster authentication tokens via a PATCH request to the...

CVE-2026-7184 Mattermost Remote Cluster PATCH API Leaks Authentication Tokens

Mattermost versions 11.6.x = 11.6.1, 11.5.x = 11.5.4, 10.11.x = 10.11.15 fail to sanitize the Remote Cluster API response on PATCH operations, which allows authenticated users with the managesecureconnections permission to obtain remote cluster authentication tokens via a PATCH request to the...

CVE-2026-7184 Mattermost Remote Cluster PATCH API Leaks Authentication Tokens

Mattermost versions 11.6.x = 11.6.1, 11.5.x = 11.5.4, 10.11.x = 10.11.15 fail to sanitize the Remote Cluster API response on PATCH operations, which allows authenticated users with the managesecureconnections permission to obtain remote cluster authentication tokens via a PATCH request to the...

CVE-2026-7184 Mattermost Remote Cluster PATCH API Leaks Authentication Tokens

Mattermost versions 11.6.x = 11.6.1, 11.5.x = 11.5.4, 10.11.x = 10.11.15 fail to sanitize the Remote Cluster API response on PATCH operations, which allows authenticated users with the managesecureconnections permission to obtain remote cluster authentication tokens via a PATCH request to the...

PT-2026-48940

Mattermost versions 11.6.x = 11.6.1, 11.5.x = 11.5.4, 10.11.x = 10.11.15 fail to sanitize the Remote Cluster API response on PATCH operations, which allows authenticated users with the manage secure connections permission to obtain remote cluster authentication tokens via a PATCH request to the...

CVE-2026-4273

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13 fail to validate that the RefreshedToken differs from the original invite token during remote cluster invite confirmation which allows an authenticated attacker to bypass token rotation and reuse the original invite token via sending a craft...