Nixpkgs security tracker

Untriaged

Permalink CVE-2026-5740

7.5 HIGH

CVSS version (CVSS): 3.1
Attack Vector (AV): Network (N)
Attack Complexity (AC): Low (L)
Privileges Required (PR): None (N)
User Interaction (UI): None (N)
Scope (S): Unchanged (U)
Confidentiality (C): None (N)
Integrity (I): None (N)
Availability (A): High (H)
Modified Attack Vector (MAV): Network (N)
Modified Attack Complexity (MAC): Low (L)
Modified Privileges Required (MPR): None (N)
Modified User Interaction (MUI): None (N)
Modified Confidentiality (MC): None (N)
Modified Scope (MS): Unchanged (U)
Modified Integrity (MI): None (N)
Modified Availability (MA): High (H)

created 3 months, 4 weeks ago Activity log

Created suggestion 3 months, 4 weeks ago

Unauthenticated WebSocket binary frame causes denial of service in Mattermost Server

Mattermost versions 11.6.x <= 11.6.0, 11.5.x <= 11.5.3, 11.4.x <= 11.4.4, 10.11.x <= 10.11.14 fail to properly validate msgpack-encoded WebSocket frames before memory allocation which allows an unauthenticated remote attacker to crash the server process and cause a full service outage for all users via a crafted binary WebSocket message sent to the public WebSocket endpoint.. Mattermost Advisory ID: MMSA-2026-00647