Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection') Affecting com.rabbitmq:amqp-client package, versions [,5.33.0)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
Do your applications use this vulnerable package?
In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.
Test your applications- Snyk IDSNYK-JAVA-COMRABBITMQ-18958663
- published19 Aug 2026
- disclosed18 Aug 2026
- creditlucianjohnhouse
Introduced: 18 Aug 2026
NewCVE-2026-63337 (opens in a new tab)How to fix?
Upgrade com.rabbitmq:amqp-client to version 5.33.0 or higher.
Overview
Affected versions of this package are vulnerable to Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection') via ProcedureDescription.computeReturnTypeAsJavaClass() in src/main/java/com/rabbitmq/tools/jsonrpc/ProcedureDescription.java. An attacker can trigger loading of attacker-chosen classes by sending a crafted JSON-RPC javaReturnType value in a system.describe response. Because the client resolves that field with Class.forName(javaReturnType) on data taken from an untrusted AMQP message, classes on the victim’s classpath are loaded with static initialization enabled. That can execute attacker-selected static initializers in the client JVM and disrupt or influence applications using the JSON-RPC tools.