CVE-2026-42527
Deserialization of Untrusted Data vulnerability in Apache Camel. The default ObjectInputFilter pattern shipped with several Apache Camel components for defense-in-depth deserialization filtering ('java.**;javax.**;org.apache.camel.**;!*', or the no-'javax.**' variant in the aggregation-repository components) uses a recursive 'java.**' glob that admits classes whose hashCode/equals/readObject methods perform network I/O, notably java.net.URL and java.net.InetAddress. When an attacker can deliver a Java-serialized payload to an affected Camel consumer, deserialization of a HashMap (or any collection that calls hashCode on its elements) containing java.net.URL keys causes the JVM to issue DNS queries to the attacker-supplied host during the deserialization side-effect. The class-level filter check passes because the resulting object's class (HashMap) is allow-listed; the DNS query is observable on an attacker-controlled DNS server, providing an out-of-band side channel. The exposure is highest on the camel-jms family because JmsBinding.extractBodyFromJms invokes ObjectMessage.getObject() unconditionally when mapJmsMessage=true (default). Affected components: camel-jms, camel-sjms, camel-amqp, camel-mina, camel-netty, camel-netty-http, camel-vertx-http, camel-infinispan, and the aggregation repository components camel-leveldb, camel-cassandraql, camel-consul, camel-sql (JDBC aggregation repository). This issue affects Apache Camel: from 4.14.0 before 4.14.8, from 4.15.0 before 4.18.3, from 4.19.0 before 4.21.0. Users are recommended to upgrade to a version that contains the CAMEL-23372 fix once available: 4.21.0 for the 4.21.x line, 4.18.3 for the 4.18.x line, and 4.14.8 for the 4.14.x line. For deployments that cannot upgrade immediately, configure a JMS-provider-side allow-list (Apache ActiveMQ Artemis 'deserializationAllowList' / 'deserializationDenyList', Apache ActiveMQ Classic 'org.apache.activemq.SERIALIZABLE_PACKAGES') as the primary mitigation, and/or override the in-code default via the endpoint-level 'deserializationFilter' option or the JVM-wide '-Djdk.serialFilter' system property with an explicit deny: '!java.net.**;java.**;javax.**;org.apache.camel.**;!*' (or '!java.net.**;java.**;org.apache.camel.**;!*' for the aggregation-repository components, which do not include javax.**).
What this means
- Exposure
- Exploitable remotely over the network, without authentication and with no action from the victim. The attack does require particular conditions, which makes it less systematic.
- Impact
- An attacker can read sensitive data, modify or destroy data and take the service offline.
- Weakness
- The application rebuilds an object from attacker-controlled data, which often leads to code execution.
- Likelihood
- Its EPSS score stays low: nothing points to imminent exploitation, which is no reason to leave it unpatched.
What to doFold into the next patch cycle. Start with the instances exposed to the internet.
Read automatically from the CVSS vector, the weakness type (CWE) and the EPSS score. The technical description above remains the one published by NIST.