CVE-2026-6957

Mattermost Plugins versions =1.1.5 fail to sanitize filenames received from federated peers before using them to construct export destination paths, which allows an administrator of a remote federated Mattermost server to write files to arbitrary locations within the target server's filestore via...

CVE-2026-6957 Path traversal in Mattermost Legal Hold plugin via unsanitized file name from federated peer allows arbitrary file write.

Mattermost Plugins versions =1.1.5 fail to sanitize filenames received from federated peers before using them to construct export destination paths, which allows an administrator of a remote federated Mattermost server to write files to arbitrary locations within the target server's filestore via...

Mattermost does not verify remote cluster channel access when processing shared channel membership removals

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel,...

GHSA-8H9W-W78C-VVR3 Mattermost does not verify remote cluster channel access when processing shared channel membership removals

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel,...

CVE-2026-28759

Mattermost multiple releases (11.4.x <= 11.4.3, 11.5.x <= 11.5.1, 10.11.x

CVE-2026-28759 Insufficient authorization in shared channel membership sync allows remote cluster to remove users from arbitrary channels

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel,...

EUVD-2026-30738

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel,...

CVE-2026-28759 Insufficient authorization in shared channel membership sync allows remote cluster to remove users from arbitrary channels

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel,...

CVE-2026-28759

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel,...

PT-2026-41640

Mattermost versions 11.5.x = 11.5.1, 10.11.x = 10.11.13, 11.4.x = 11.4.3 fail to validate that a remote cluster has access to a channel before processing membership removal requests during shared channel membership sync, which allows a malicious remote cluster to remove any user from any channel,...

CVE-2026-31740

A flaw was found in the Linux kernel's rz-mtu3-cnt counter driver. A race condition exists where multiple sub-drivers can simultaneously attempt to assign their device pointers to a shared channel member. This can result in the counter sub-driver performing power management actions on an unintend...

EUVD-2026-26553

In the Linux kernel, the following vulnerability has been resolved: counter: rz-mtu3-cnt: do not use struct rzmtu3channel's dev member The counter driver can use HW channels 1 and 2, while the PWM driver can use HW channels 0, 1, 2, 3, 4, 6, 7. The dev member is assigned both by the counter drive...

CVE-2026-4274

Mattermost CVE-2026-4274 affects multiple release lines: 11.2.x <= 11.2.2, 10.11.x <= 10.11.10, 11.4.x <= 11.4.0, and 11.3.x

CVE-2026-4274 Insufficient authorization in shared channel membership sync grants team-level access instead of channel-level access

Mattermost versions 11.2.x = 11.2.2, 10.11.x = 10.11.10, 11.4.x = 11.4.0, 11.3.x = 11.3.1 fail to restrict team-level access when processing membership sync from a remote cluster, which allows a malicious remote cluster to grant a user access to an entire private team instead of only the shared...

CVE-2026-23286

A flaw was found in the Linux kernel's ATM LANE LAN Emulation module. When an Asynchronous Transfer Mode Virtual Channel Connection atmvcc is shared across multiple entries, a vulnerability in the lecarpclearvccs function can lead to a null-pointer dereference. This occurs when the function...

Quantum CDMA-Based Continuous Variable Quantum Key Distribution Using Chaotic Phase Shifters

We present a quantum code-division multiple-access q-CDMA framework for multiuser continuous-variable quantum key distribution CV-QKD over a shared quantum channel. The proposed architecture employs chaotic phase shifters to encode and decode quantum states, enabling efficient multiplexing and...

CVE-2024-39274

Mattermost versions 9.9.x = 9.9.0, 9.5.x = 9.5.6, 9.7.x = 9.7.5 and 9.8.x = 9.8.1 fail to properly validate that the channel that comes from the sync message is a shared channel, when shared channels are enabled, which allows a malicious remote to add users to arbitrary teams and channels...

Improper Input Sanitization

github.com/mattermost/mattermost-server is vulnerable to improper input sanitization. The vulnerability is due to insufficient sanitization of user data during shared channel membership synchronization, which allows an attacker from a malicious or compromised remote cluster to access sensitive us...

CVE-2025-9076

Mattermost versions 10.10.x = 10.10.1 fail to properly sanitize user data during shared channel membership synchronization, which allows malicious or compromised remote clusters to access sensitive user information via unsanitized user objects. This vulnerability affects Mattermost Server instanc...

CVE-2025-9076 Mattermost Server exposes sensitive user credentials during shared channel membership synchronization

Mattermost versions 10.10.x = 10.10.1 fail to properly sanitize user data during shared channel membership synchronization, which allows malicious or compromised remote clusters to access sensitive user information via unsanitized user objects. This vulnerability affects Mattermost Server instanc...