Summary
RabbitMQ Java client ValueReader: Unbounded recursive table/array nesting causes StackOverflowError DoS
ValueReader.readTable() and readArray() recursively call readFieldValue() with no depth limit. A malicious AMQP peer can crash the client JVM by sending a deeply nested table structure.
Vulnerable Code
src/main/java/com/rabbitmq/client/impl/ValueReader.java lines 139-155 and 237-249:
private static Map<String, Object> readTable(DataInputStream in) throws IOException {
long tableLength = unsignedExtend(in.readInt());
// ...
while(tableIn.available() > 0) {
String name = readShortstr(tableIn);
Object value = readFieldValue(tableIn); // recursive call
}
}
static Object readFieldValue(DataInputStream in) throws IOException {
switch(in.readUnsignedByte()) {
case 'F': value = readTable(in); // mutual recursion
case 'A': value = readArray(in); // mutual recursion
}
}
Attack Scenario
A malicious AMQP server (or MitM) sends a connection.start frame with ~580 levels of nested tables. Each level costs ~7 bytes (4-byte length + 1-byte key length + 1-byte key + 1-byte type tag), totaling ~4060 bytes within the 131,072 byte max frame size. With the default JVM stack (~512KB, ~864 bytes/frame), this triggers StackOverflowError, killing the I/O thread.
Exploitable pre-authentication since connection.start is the very first server frame.
CWE
CWE-674: Uncontrolled Recursion
Impact
Denial of service. StackOverflowError kills the client I/O thread.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
Add a depth counter to readTable/readArray/readFieldValue and throw MalformedFrameException when exceeding a threshold (e.g., 32).
Frequently Asked Questions
- What is CVE-2026-69220? CVE-2026-69220 is a high-severity security vulnerability in com.rabbitmq:amqp-client (maven), affecting versions <= 5.33.0. It is fixed in 5.33.1.
- Which versions of com.rabbitmq:amqp-client are affected by CVE-2026-69220? com.rabbitmq:amqp-client (maven) versions <= 5.33.0 is affected.
- Is there a fix for CVE-2026-69220? Yes. CVE-2026-69220 is fixed in 5.33.1. Upgrade to this version or later.
- Is CVE-2026-69220 exploitable, and should I be worried? Whether CVE-2026-69220 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-69220 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-69220? Upgrade
com.rabbitmq:amqp-clientto 5.33.1 or later.