CVE-2026-78162
Deserialization of Untrusted Data vulnerability in Apache Camel. This issue affects Apache Camel: from 4.0.0 before 4.18.5, from 4.19.0 before 4.22.1. The camel-hazelcast component applies a default Hazelcast JavaSerializationFilterConfig to the instances it creates from its own configuration, a protection introduced by CVE-2026-43865. That change did not reach two of the configuration paths Camel builds itself, so those paths continued to create Hazelcast instances whose Java deserialization is unrestricted. ReplicatedHazelcastAggregationRepository extends HazelcastAggregationRepository but overrides doStart() without calling super.doStart(), keeping its own copy of the bootstrap block, and therefore never received the filter: a route using it without supplying a hazelcastInstance starts a Hazelcast member that deserializes values read from the backing ReplicatedMap with no class restriction. HazelcastDefaultComponent#getOrCreateHzClientInstance() builds its own ClientConfig when hazelcastMode=client is selected and neither a referenced ClientConfig nor hazelcastConfigUri is supplied, and likewise applied no filter, so client-mode endpoints behaved differently from node-mode endpoints for an otherwise identical configuration. In both cases an attacker able to publish into the Hazelcast cluster that the affected instance is attached to can cause a serialized Java object of their choosing to be deserialized inside Hazelcast's own serialization layer, before Camel processes the exchange, resulting in remote code execution. Hazelcast clusters have neither authentication nor TLS enabled by default. Selecting client mode is a topology choice rather than a security option, so neither path required the deployment to opt in to unsafe behaviour. Users are recommended to upgrade to version 4.23.0, which fixes the issue. If users are on the 4.22.x releases stream, then they are suggested to upgrade to 4.22.1. If users are on the 4.18.x releases stream, then they are suggested to upgrade to 4.18.5. The 4.14.x releases stream and earlier reached end of life before this issue was resolved and will not receive a fix, so deployments on those lines must move to a supported release. For deployments that cannot upgrade immediately, supply an explicit Hazelcast configuration carrying a JavaSerializationFilterConfig, or inject a pre-built HazelcastInstance, since a user-supplied configuration is never overwritten by Camel. Alternatively set the JVM-wide filter -Djdk.serialFilter=!java.net.;java.;javax.;org.apache.camel.;!* and enable Hazelcast cluster authentication and TLS to restrict who can reach the cluster.
Executive briefing
The source record describes: Deserialization of Untrusted Data vulnerability in Apache Camel. This issue affects Apache Camel: from 4.0.0 before 4.18.5, from 4.19.0 before 4.22.1. The camel-hazelcast component applies a default Hazelcast JavaSerializationFilterConfig to the instances it creates from its own configuration, a protection introduced by CVE-2026-43865. That change did not reach two of the configuration paths Camel builds itself, so those paths continued to create Hazelcast instances whose Java deserialization is unrestricted. ReplicatedHazelcastAggregationRepository extends HazelcastAggregationRepository but overrides doStart() without calling super.doStart(), keeping its own copy of the bootstrap block, and therefore never received the filter: a route using it without supplying a hazelcastInstance starts a Hazelcast member that deserializes values read from the backing ReplicatedMap with no class restriction. HazelcastDefaultComponent#getOrCreateHzClientInstance() builds its own ClientConfig when hazelcastMode=client is selected and neither a referenced ClientConfig nor hazelcastConfigUri is supplied, and likewise applied no filter, so client-mode endpoints behaved differently from node-mode endpoints for an otherwise identical configuration. In both cases an attacker able to publish into the Hazelcast cluster that the affected instance is attached to can cause a serialized Java object of their choosing to be deserialized inside Hazelcast's own serialization layer, before Camel processes the exchange, resulting in remote code execution. Hazelcast clusters have neither authentication nor TLS enabled by default. Selecting client mode is a topology choice rather than a security option, so neither path required the deployment to opt in to unsafe behaviour. Users are recommended to upgrade to version 4.23.0, which fixes the issue. If users are on the 4.22.x releases stream, then they are suggested to upgrade to 4.22.1. If users are on the 4.18.x releases stream, then they are suggested to upgrade to 4.18.5. The 4.14.x releases stream and earlier reached end of life before this issue was resolved and will not receive a fix, so deployments on those lines must move to a supported release. For deployments that cannot upgrade immediately, supply an explicit Hazelcast configuration carrying a JavaSerializationFilterConfig, or inject a pre-built HazelcastInstance, since a user-supplied configuration is never overwritten by Camel. Alternatively set the JVM-wide filter -Djdk.serialFilter=!java.net.;java.;javax.;org.apache.camel.;!* and enable Hazelcast cluster authentication and TLS to restrict who can reach the cluster. The practical risk depends on whether an affected product/version is present, reachable and configured in an exploitable way. Review the affected-product evidence and linked vendor advisories before assigning exposure status.
Evidence confidence: Moderate Evidence-derived, not an exploitability verdict
Severity & attack characteristics
CVSS vector:CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Technical explanation & impact
The technical mechanism is not expanded beyond the source description unless a referenced advisory supplies additional evidence. Read the linked vendor/CERT advisories for root-cause detail.
Potential impact must be interpreted from the published CVSS impact metrics and the affected component. A CVSS impact score is not proof that a particular asset is exploitable.
Weakness classification
CWE-502Affected products and versions
Products below are parsed from NVD vulnerable CPE configuration entries. Version boundaries are shown as published; verify applicability with the vendor.
| Vendor | Product | Version evidence |
|---|---|---|
| apache | camel | from (inclusive) 4.19.0; before 4.22.1 |
Remediation & validation
- Identify exposure by comparing the affected product and version ranges with your asset inventory, SBOM and externally exposed services.
- Review the linked vendor security advisory or patch notes. Upgrade to a vendor-confirmed fixed release; do not infer a fixed version from the CVE description.
- Until patched, consider restricting network access or disabling the affected feature where operationally safe. These are temporary controls, not a substitute for a vendor fix.
- Validate the remediation with a version check and vulnerability rescan, then retain change evidence.
No fixed version is displayed unless it is explicitly established by a vendor advisory. Follow the vendor's release notes for exact product and branch applicability.
Vendor advisories, patches & exploit references
- https://camel.apache.org/security/CVE-2026-43865.html PATCH security@apache.org
- https://camel.apache.org/security/CVE-2026-78162.html PATCH security@apache.org
- https://github.com/apache/camel/pull/25566 PATCH security@apache.org
- https://github.com/apache/camel/pull/25595 PATCH security@apache.org
- https://github.com/apache/camel/pull/25599 PATCH security@apache.org
- https://github.com/apache/camel/pull/25600 PATCH security@apache.org
- https://issues.apache.org/jira/browse/CAMEL-24413 PATCH security@apache.org
- https://issues.apache.org/jira/browse/CAMEL-24420 PATCH security@apache.org