rabbitmq-java-client — security advisory
The RabbitMQ Java client library allows Java and JVM-based applications to connect to and interact with RabbitMQ nodes. Prior to 5.33.0, com.rabbitmq.tools.jsonrpc.ProcedureDescription receives a javaReturnType value in an untrusted system.describe response and passes it through JSONUtil.tryFill, setJavaReturnType, and computeReturnTypeAsJavaClass to Class.forName(javaReturnType) with initialization enabled. An attacker able to answer the JsonRpcClient request through a shared broker or network interception can select a class already present in the victim JVM and trigger its static initializer, while JsonRpcClient.java later passes getReturnType output to mapper.parse and may also create type confusion. Successful exploitation can affect confidentiality, integrity, and availability in the client process. This issue is fixed in version 5.33.0.
- Products
- rabbitmq-java-client
- Affected versions
- 5.0.0-1, 5.0.0-1.1, 5.0.0-2
- Fixed versions
- Not specified
- CVEs
- CVE-2026-63337
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 03:11 UTC · Revision 1
Source evidence
The RabbitMQ Java client library allows Java and JVM-based applications to connect to and interact with RabbitMQ nodes. Prior to 5.33.0, com.rabbitmq.tools.jsonrpc.ProcedureDescription receives a javaReturnType value in an untrusted system.describe response and passes it through JSONUtil.tryFill, setJavaReturnType, and computeReturnTypeAsJavaClass to Class.forName(javaReturnType) with initialization enabled. An attacker able to answer the JsonRpcClient request through a shared broker or network interception can select a class already present in the victim JVM and trigger its static initializer, while JsonRpcClient.java later passes getReturnType output to mapper.parse and may also create type confusion. Successful exploitation can affect confidentiality, integrity, and availability in the client process. This issue is fixed in version 5.33.0.
osv:UBUNTU-CVE-2026-63337
rabbitmq-java-client
Fixed versions: Not specified
rabbitmq-java-client
Fixed versions: Not specified
rabbitmq-java-client
Fixed versions: Not specified
rabbitmq-java-client
Fixed versions: Not specified
rabbitmq-java-client
Fixed versions: Not specified
rabbitmq-java-client
Fixed versions: Not specified
Complete source record
{
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"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-63337",
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"summary": "The RabbitMQ Java client library allows Java and JVM-based applications to connect to and interact with RabbitMQ nodes. Prior to 5.33.0, com.rabbitmq.tools.jsonrpc.ProcedureDescription receives a javaReturnType value in an untrusted system.describe response and passes it through JSONUtil.tryFill, setJavaReturnType, and computeReturnTypeAsJavaClass to Class.forName(javaReturnType) with initialization enabled. An attacker able to answer the JsonRpcClient request through a shared broker or network interception can select a class already present in the victim JVM and trigger its static initializer, while JsonRpcClient.java later passes getReturnType output to mapper.parse and may also create type confusion. Successful exploitation can affect confidentiality, integrity, and availability in the client process. This issue is fixed in version 5.33.0.",
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"modified": "2026-10-17T13:00:32.266043394Z",
"provider": "osv",
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"references": [
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"https://www.cve.org/CVERecord?id=CVE-2026-63337"
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"source_id": "core-osv",
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"published_at": "2026-08-18T17:17:00+00:00"
}