Talend Jobserver CVE-2026-6264

Talend JobServer and Talend Runtime with JMX monitoring port exposed and accessible over network. Talend ESB Runtime affected only if JMX monitoring port is explicitly enabled (disabled by default in R2024-07-RT and later). Remote unauthenticated attacker with network access to JMX port. No victim interaction required.

This represents a critical real-world risk despite lack of confirmed active exploitation. The CVSS 9.8 score accurately reflects severity: network-accessible (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), with complete impact to confidentiality, integrity, and availability (C:H/I:H/A:H). The vulnerability is highly automatable-attackers can scan for exposed JMX ports (commonly 8999 or custom ports) and exploit them programmatically without authentication barriers. The primary mitigating factor is that JMX monitoring ports may not be internet-exposed in well-architected environments, but misconfigured cloud deployments, containerized workloads, or legacy network perimeters could expose these interfaces. The fact that Talend ESB Runtime disables the JMX monitoring port by default from R2024-07-RT suggests vendor recognition of the attack surface. Organizations running earlier versions with exposed JMX ports face immediate risk of full system compromise. No public exploit identified at time of analysis, but the attack technique is well-documented in security research. This is a clear patching priority for any organization running affected Talend products with accessible JMX interfaces.

An attacker performs network reconnaissance scanning for exposed JMX ports on internet-facing or internal networks hosting Talend infrastructure. Upon discovering an open JMX monitoring port (default 8999 or environment-specific), the attacker connects without authentication and enumerates available MBeans using standard JMX client tools. The attacker then invokes MBean methods to load malicious serialized Java objects or directly execute system commands through exposed management interfaces, achieving arbitrary code execution with the privileges of the Talend JobServer process. From this foothold, the attacker can exfiltrate sensitive data processed by ETL jobs, pivot to connected databases and data sources, or establish persistent access to the enterprise data integration environment.