Bulletin ID: 2026-147-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 10/22/2026 13:30 PM PDT Description: aws-c-mqtt is a C99 implementation of the MQTT 3.1.1 and MQTT5 specifications, distributed as part of the AWS Common Runtime (CRT) and bundled in the AWS IoT Device SDK for C++ v2. We identified CVE-2026-115417, a memory allocation with excessive size value (CWE-789) in the library's MQTT 3.1.1 compatibility adapter. Under certain conditions, a remote actor could cause a denial of service of the client process. Impacted versions: >= 0.9.1 AND < 0.16.2 Please refer to the article below for the most up-to-date and complete information related to this AWS Security Bulletin. Read this article