CVE-2026-41731
HIGHJsonKafkaHeaderMapper and the deprecated DefaultKafkaHeaderMapper matched type headers against trusted packages using a prefix check, meaning that trusting any package implicitly trusted…
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Description
JsonKafkaHeaderMapper and the deprecated DefaultKafkaHeaderMapper matched type headers against trusted packages using a prefix check, meaning that trusting any package implicitly trusted all of its subpackages. Combined with Jackson's default bean deserialization, a producer could supply crafted header values that caused the consumer to deserialize arbitrary JDK types.
Affected versions: Spring for Apache Kafka 4.0.0 through 4.0.5; 3.3.0 through 3.3.15; 3.2.0 through 3.2.13; 2.9.0 through 2.9.13; 2.8.0 through 2.8.11.
Affected Products
spring for apache kafkavmwareDetection & mitigation playbook
Vendor / applianceDetect
Inventory every vmware spring for apache kafka deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for remote code execution at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Remediation status
No patch has shipped for CVE-2026-41731 yet — track the vmware spring for apache kafka advisory for a fixed release and apply the workarounds below in the meantime.
Mitigate without a patch
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2026-41731 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2026-41731. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-41731 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2026-41731 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.