CVE-2026-15555 Red Hat CVE debrief

Who should care

Organizations using JBoss, particularly those with exposed or internet-facing deployments, should prioritize patching this vulnerability to prevent potential remote code execution attacks.

Technical summary

The Infinispan session replication path in JBoss deserializes replicated session data via the JBoss Marshalling River unmarshaller without class filtering, enabling remote code execution via deserialization gadget chains on every cluster node. This vulnerability has a CVSS score of 8.8 and is considered high severity. Affected product deployments exist in managed environments and require an owner for follow-up. Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance. Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed. The vulnerability affects JBoss marshalling and requires immediate attention to prevent potential remote code execution attacks. The CVSS score indicates a high severity, and organizations should prioritize patching this vulnerability to prevent potential remote code execution attacks. Compensating controls, such as restricting access to the affected systems or monitoring for suspicious activity, can be implemented while remediation is scheduled and verified. Conduct thorough inventory checks to identify and address any potential exposure. Consider implementing additional security measures, such as input validation and output encoding, to prevent similar attacks. The CVE record indicates a flaw in JBoss marshalling, specifically in the Infinispan session replication path, which deserializes replicated session data via the JBoss Marshalling River unmarshaller without class filtering. This allows for remote code execution via deserialization gadget chains on every cluster node. The CVSS score is 8.8, indicating a high severity. The NVD entry is currently Awaiting Analysis, and organizations should review compensating controls for exposed systems while remediation is scheduled and verified. Check relevant monitoring, detection, and logs for exposed assets that need extra review. Track exceptions, retest remediated assets, and close the item only after evidence is documented. The vulnerability has not been modified since its publication on 2026-08-11T09:17:12.540Z. The CVE record was published on 2026-08-11T09:17:12.540Z and has not been modified.

Defensive priority

Organizations using JBoss should prioritize patching this vulnerability to prevent potential remote code execution attacks.

Recommended defensive actions

• Apply patches or updates provided by the vendor to address the vulnerability in JBoss marshalling.
• Implement compensating controls, such as restricting access to the affected systems or monitoring for suspicious activity.
• Conduct thorough inventory checks to identify and address any potential exposure.
• Consider implementing additional security measures, such as input validation and output encoding, to prevent similar attacks.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed.

Evidence notes

The CVE-2026-15555 record indicates a flaw in JBoss marshalling, specifically in the Infinispan session replication path, which deserializes replicated session data via the JBoss Marshalling River unmarshaller without class filtering. This allows for remote code execution via deserialization gadget chains on every cluster node. The CVSS score is 8.8, indicating a high severity.

Official resources