Vulnerability · Published Oct 22, 2026 · Assigned by AMZN
CVE-2026-115417Memory allocation with excessive size value in the MQTT 3.1.1 compatibility adapter in aws-c-mqtt
High 7.5
In plain English
A high-severity security flaw in aws-c-mqtt from AWS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 29% of all known vulnerabilities).
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.4%top 71.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Memory allocation with excessive size value in the MQTT 3.1.1 compatibility adapter in AWS aws-c-mqtt before 0.16.2 might allow a remote actor to cause a denial of service of the client application. To remediate this issue, users should upgrade to aws-c-mqtt 0.16.2 or later, or to an AWS Common Runtime or AWS IoT Device SDK release that bundles it.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| AWS | aws-c-mqtt | 0.9.1 – before 0.16.2 |
Weakness: CWE-789 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://github.com/awslabs/aws-c-mqtt/releases/tag/v0.16.2 release-notes, patch
- https://github.com/awslabs/aws-c-mqtt/security/advisories/GHSA-g3x5-86mr-65p5 third-party-advisory
- https://aws.amazon.com/security/security-bulletins/2026-147-aws/ vendor-advisory