CVE-2026-43865
HIGH 8.1Deserialization of Untrusted Data vulnerability in Apache Camel Hazelcast component. The camel-hazelcast component creates and manages Hazelcast instances using a default configuration that applies no Java deserialization filter. When Camel builds the Hazelcast Config itself - that is, when no user-supplied HazelcastInstance, hazelcastConfigUri, or referenced Config bean is provided - neither Hazelcast's JavaSerializationFilterConfig nor a Camel-side ObjectInputFilter is configured, so objects received over the Hazelcast cluster protocol are deserialized inside Hazelcast's own serialization layer (ObjectInputStream.readObject) before Camel ever processes them. An attacker who can join or otherwise reach the Hazelcast cluster can publish a crafted serialized Java object that is then deserialized on every Camel node, resulting in remote code execution. The exposure is present by default and requires no opt-in endpoint configuration: any route using a hazelcast consumer (hazelcast-topic, hazelcast-queue, hazelcast-seda, hazelcast-map, hazelcast-multimap, hazelcast-replicatedmap, hazelcast-list, hazelcast-set), as well as the HazelcastAggregationRepository and HazelcastIdempotentRepository, is affected whenever the managed instance is created from Camel's default configuration. This issue affects Apache Camel: from 4.0.0 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 version 4.21.0, which fixes the issue. If users are on the 4.14.x LTS releases stream, then they are suggested to upgrade to 4.14.8. If users are on the 4.18.x releases stream, then they are suggested to upgrade to 4.18.3. The fix makes Camel apply a default Hazelcast JavaSerializationFilterConfig (whitelisting the java., javax. and org.apache.camel. class-name prefixes and blacklisting java.net.) to instances it creates from its own default configuration, while leaving any user-supplied Config or HazelcastInstance untouched. For deployments that cannot upgrade immediately, configure a deserialization filter on the Hazelcast instance (Hazelcast JavaSerializationFilterConfig, or the JVM-wide system property -Djdk.serialFilter=!java.net.**;java.**;javax.**;org.apache.camel.**;!*) and enable Hazelcast cluster authentication and TLS to restrict who can reach the cluster.
Severe if exploited (CVSS 8.1), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.8%chance of exploitation in 30 days · 53rd percentile
Impact if exploited
8.1CVSS 3.1 · HIGH
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ✓Privileges: No account or privileges required
- ✓User interaction: No user interaction needed
- ⚠Complexity: Needs a race window or specific setup
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-43865/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-43865/poc.json
Weakness (CWE)
- CWE-502: Deserialization of Untrusted Data
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Apache | Camel | ≥ 4.0.0 and < 4.14.8 |
| Apache | Camel | ≥ 4.15.0 and < 4.18.3 |
| Apache | Camel | ≥ 4.19.0 and < 4.21.0 |
All CVSS metrics
- HIGH 8.1 v3.1 · ADP Primary
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - HIGH 8.1 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H