Description
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.
Published: 2026-10-19
Score: 10 Critical
EPSS: n/a
KEV: No
Impact: Remote Code Execution
Action: Immediate Patch
AI Analysis

Impact

The vulnerability stems from Apache Camel’s camel‑hazelcast component failing to apply a JavaSerializationFilterConfig to Hazelcast instances it creates in two configuration paths, leaving Java deserialization unprotected. This flaw classifies as CWE‑502, allowing an attacker who can publish data to the cluster to deliver a crafted serialized Java object that is deserialized within Hazelcast’s own layer before Camel processes it, resulting in arbitrary code execution on the host running the affected Camel instance.

Affected Systems

Apache Camel versions 4.0.0 through 4.18.4, 4.19.0 through 4.22.0 are impacted. The fix is delivered in Apache Camel 4.23.0 and in minor releases 4.22.1 (for the 4.22.x stream) and 4.18.5 (for the 4.18.x stream). Older lines such as 4.14.x were declared end‑of‑life and will not receive a patch, so those deployments must migrate to a supported release.

Risk and Exploitability

The CVSS score of 10.0 signals critical severity, and the lack of authentication or TLS in Hazelcast by default makes the attack vector likely network‑based, where an attacker can publish a malicious object to the cluster. EPSS is not available, and the vulnerability is not listed in CISA’s KEV catalogue, but the combination of high severity and an easy to trigger exploitation path places this flaw among the highest priority risks for systems running the affected Camel versions.

Generated by OpenCVE AI on October 19, 2026 at 11:23 UTC.

Remediation

Vendor Solution

Upgrade to Apache Camel 4.23.0, which fixes the issue. Users on the 4.22.x releases stream should upgrade to 4.22.1. Users on the 4.18.x releases stream should 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. The fix adds an applyDefault(ClientConfig) overload to HazelcastSerializationFilterHelper and calls the helper on both previously uncovered paths, so every Hazelcast configuration that Camel builds itself now carries the default filter, which whitelists the class name prefixes java., javax. and org.apache.camel. and blacklists java.net. A user-supplied Config, ClientConfig or HazelcastInstance is still left untouched.

Vendor Workaround

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.

OpenCVE Recommended Actions

  • Upgrade Apache Camel to version 4.23.0 (or upgrade to 4.22.1 if on the 4.22.x stream, or to 4.18.5 if on the 4.18.x stream).
  • If an immediate upgrade is not feasible, supply an explicit Hazelcast configuration that includes a JavaSerializationFilterConfig or inject a pre‑built HazelcastInstance, ensuring that the Camel component does not override the filter.
  • Set a JVM‑wide serialization filter using -Djdk.serialFilter=!java.net.;java.;javax.;org.apache.camel.;!* and enable Hazelcast cluster authentication and TLS to restrict access to the cluster.

Generated by OpenCVE AI on October 19, 2026 at 11:23 UTC.

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History

Mon, 19 Oct 2026 10:30:00 +0000

Type Values Removed Values Added
Description 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.
Title Apache Camel: Camel-Hazelcast Managed Instances Missing Java Deserialization Filter (Incomplete Fix for CVE-2026-43865)
Weaknesses CWE-502
References
Metrics cvssV4_0

{'score': 10, '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'}

Subscriptions

No data.

cve-icon MITRE

Status: PUBLISHED

Assigner: apache

Published:

Updated: 2026-10-19T10:03:57.474Z

Reserved: 2026-08-23T12:12:19.275Z

Link: CVE-2026-78162

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-19T11:17:19.037

Modified: 2026-10-19T11:17:19.037

Link: CVE-2026-78162

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-19T11:30:16Z

Weaknesses
  • CWE-502

    Deserialization of Untrusted Data