CVE-2026-50161
Description
A flaw was found in libre. An integer overflow vulnerability exists in the websock_decode() function when validating a masked WebSocket frame that uses 64-bit extended length encoding. This flaw can cause a heap buffer overflow, allowing a remote attacker to achieve attacker-controlled heap corruption or denial of service after the HTTP WebSocket upgrade handshake. This affects applications that implement a WebSocket server using websock_accept() or websock_accept_proto().
Statement
This vulnerability is rated as Critical severity because it permits an unauthenticated remote attacker across the network to cause heap corruption or crash the service with no user interaction. Within the Red Hat ecosystem, libre is not distributed in Red Hat Enterprise Linux and is only available through community repositories such as EPEL and Fedora. Impact is confined to environments running network services that utilize this library to accept incoming WebSocket connections.
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory; Execute Unauthorized Code or Commands
Write operations could cause memory corruption. In some cases, an adversary can modify control data such as return addresses in order to execute unexpected code.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
Attempting to access out-of-range, invalid, or unauthorized memory could cause the product to crash.
Other
Technical Impact: Unexpected State
Subsequent write operations can produce undefined or unexpected results.
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