CVE-2026-63336
mediumpriority · track · 0EPSS 0.003 · 23 %ileUSEPSS · scored 2026-10-27
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.client.ConnectionFactory.useSslProtocol() and ConnectionFactory.useSslProtocol(String) configure com.rabbitmq.client.TrustEverythingTrustManager and leave hostname verification disabled, causing arbitrary server certificates, including self-signed certificates, to be accepted. A network attacker able to intercept a TLS connection can impersonate the RabbitMQ broker, read protected AMQP traffic, and modify traffic without certificate or hostname validation. The fix changes the production TLS helpers to use the JVM default trust store and enables hostname verification, while retaining an explicitly named development-only no-verification helper. This issue is fixed in version 5.33.0.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 1.2–5.1
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (1)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- GHSA-5m9f-rphj-c435RabbitMQ Java client: TrustEverythingTrustManager used by default in useSslProtocol() enables MITM2026-08-18ghsa · osvUS
## Vulnerability Summary `com.rabbitmq.client.TrustEverythingTrustManager` accepts ANY TLS certificate (including null chains) and is used as the default trust manager when calling `ConnectionFactory.useSslProtocol()` without arguments. Combined with hostname verification being disabled by default, this enables trivial man-in-the-middle attacks. ## Affected Components - `com.rabbitmq.client.TrustEverythingTrustManager` — accepts any certificate - `com.rabbitmq.client.ConnectionFactory.useSslProtocol()` — uses TrustEverythingTrustManager - Hostname verification disabled by default (`enableHostnameVerification()` must be called explicitly) - `com.rabbitmq.client.ConnectionFactory.getPassword()` — returns plaintext with no redaction - Default port 5672 (plaintext) with PLAIN SASL — credentials sent unencrypted ## POC (Verified on Java 21, amqp-client 5.25.0) ```java // TrustEverythingTrustManager accepts ANY certificate including null TrustEverythingTrustManager tm = new TrustEverythingTrustManager(); tm.checkServerTrusted(null, "RSA"); // No exception — accepts null cert chain tm.getAcceptedIssuers(); // Returns empty array — trusts all CAs // ConnectionFactory defaults ConnectionFactory factory = new ConnectionFactory(); factory.useSslProtocol(); // Uses TrustEverythingTrustManager internally // enableHostnameVerification() NOT called by default // Credential exposure factory.setPassword("secret_password_123"); factory.getPassword(); // Returns "secret_password_123" — no redaction // Default plaintext port factory.getPort(); // 5672 (plaintext, not 5671/TLS) // PLAIN SASL sends cleartext credentials PlainMechanism pm = new PlainMechanism(); // handleChallenge() sends username+password in cleartext ``` ## Attack Scenarios 1. **MITM**: Attacker presents self-signed cert → `TrustEverythingTrustManager` accepts it → all RabbitMQ traffic intercepted 2. **Credential theft**: Default plaintext port (5672) + PLAIN SASL = credentials readable on network 3. **DNS rebinding**: No hostname verification → attacker DNS record → MITM without cert 4. **Logging exposure**: `getPassword()` returns plaintext → credentials in logs/stack traces ## Suggested Fix 1. Deprecate `TrustEverythingTrustManager` — it should never be used in production 2. `useSslProtocol()` should use the JVM default trust store, not TrustEverything 3. Enable hostname verification by default 4. Redact password in `getPassword()` or remove the public getter 5. Warn when using PLAIN SASL without TLS
sources
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references (6) nvd
External citations — patches, advisories, analysis.
- https://github.com/rabbitmq/rabbitmq-java-client/commit/1e7deb2e6020c9793a81385a53ea378ec63b9339
- https://github.com/rabbitmq/rabbitmq-java-client/commit/a4bf571dd368765baaa9cecfae68ce09f1bdcc01
- https://github.com/rabbitmq/rabbitmq-java-client/pull/1999
- https://github.com/rabbitmq/rabbitmq-java-client/pull/2001
- https://github.com/rabbitmq/rabbitmq-java-client/releases/tag/v5.33.0
- https://github.com/rabbitmq/rabbitmq-java-client/security/advisories/GHSA-5m9f-rphj-c435
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