RabbitMQ: JSONReader in the default JSON-RPC mapper never terminates on truncated input, causing DoS

Why it is Amber

• CVSS 7.5 high
• Public exploit or proof of concept referenced
• Remotely exploitable without logging in
• On your watchlist: Maven

Affected packages

References

• https://github.com/advisories/GHSA-cqgh-8p3p-mx4m
• https://github.com/rabbitmq/rabbitmq-java-client/security/advisories/GHSA-cqgh-8p3p-mx4m
• https://nvd.nist.gov/vuln/detail/CVE-2026-106121
• https://github.com/rabbitmq/rabbitmq-java-client/pull/2100
• https://github.com/rabbitmq/rabbitmq-java-client/commit/25fad817291feff3195c32620117d295598f8b41
• https://github.com/rabbitmq/rabbitmq-java-client/releases/tag/v5.37.0
• https://github.com/advisories/GHSA-cqgh-8p3p-mx4m

Original description

The RabbitMQ Java client library allows Java and JVM-based applications to connect to and interact with RabbitMQ nodes. Prior to 5.37.0, com.rabbitmq.tools.json.JSONReader.read() fails to terminate when input ends inside a quoted string or a line comment because its string and whitespace scanners do not stop at CharacterIterator.DONE. The default DefaultJsonRpcMapper passes JSON-RPC message bodies to this parser for JsonRpcServer and client replies. A truncated string causes the parser to append replacement end markers until heap exhaustion, while a line comment without a terminating newline can keep a thread consuming CPU indefinitely, resulting in denial of service. This issue is fixed in version 5.37.0.