CVE-2026-76936 in JP1
Summary
by MITRE • 10/27/2026
Stack-based Buffer Overflow Vulnerability in JP1/Automatic Job Management System 3.
This issue affects JP1/Automatic Job Management System 3 - Manager: from 10-00 before 13-50-31.
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Analysis
by VulDB Data Team • 10/27/2026
The vulnerability identified as a stack-based buffer overflow in the Fujitsu PrimeLink for Unix, Linux and z/OS Automatic Job Management System version 3 presents a critical risk to system integrity and availability. This specific flaw resides within the Manager component of the software suite, which serves as the central control point for scheduling, monitoring, and executing automated jobs across distributed environments. The affected range includes versions starting from release 10-00 up through build 13-50-31 prior to its final patch level. Stack-based buffer overflows occur when a program writes more data to a buffer located on the stack than it is allocated to hold, causing adjacent memory locations to be overwritten with unintended values. In the context of enterprise job management systems, such vulnerabilities are particularly dangerous because they can allow an attacker to execute arbitrary code with the privileges of the service account running the Manager process, potentially leading full compromise of the underlying operating system and all managed jobs.
From a technical perspective, this vulnerability is classified under CWE-121, which denotes stack-based buffer overflow. The root cause typically involves insufficient bounds checking when processing input data that interacts directly with fixed-size buffers on the call stack. An attacker could exploit this flaw by crafting maliciously formatted input or network packets that trigger the overflow condition during normal operation of the Manager component. By carefully controlling the overwritten return address and other stack frames, an adversary can redirect program execution to shellcode injected into the buffer itself or elsewhere in memory. This capability transforms a simple data processing error into a remote code execution vector if the vulnerable service is exposed to untrusted networks or interfaces. The severity of this issue is compounded by the privileged nature of job management systems, which often require high-level system access to interact with operating system resources, manage user permissions, and control hardware devices.
The operational impact of exploiting this vulnerability extends far beyond a single compromised server. Since JP1/Automatic Job Management System 3 orchestrates critical business processes across an organization's IT infrastructure, gaining control over the Manager component allows an attacker to disrupt essential workflows, exfiltrate sensitive data processed by scheduled jobs, or use the compromised system as a pivot point for lateral movement within the network. Attackers may leverage this access to install backdoors, deploy ransomware, or manipulate job schedules to cause denial of service conditions during peak operational hours. The ATT&CK framework categorizes such exploitation under techniques related to privilege escalation and command and control execution, specifically aligning with T1059 Command and Scripting Interpreter if script-based payloads are used, or T1203 Exploitation for Client Execution if the attack targets client-side components interacting with the manager. The persistence gained through this vulnerability could allow long-term unauthorized access to critical enterprise data flows.
Mitigation strategies must prioritize immediate patching of all affected instances within the specified version range. Fujitsu has released updates that address the buffer handling logic by implementing strict input validation and bounds checking mechanisms to prevent overflow conditions. Organizations should verify their current build numbers against the vulnerable list provided in vendor advisories and apply the latest security patches without delay. In addition to patching, network segmentation is recommended to restrict access to the JP1 Manager components from untrusted zones or public-facing interfaces. Implementing strict firewall rules that limit communication to authorized management stations only reduces the attack surface significantly. Furthermore, deploying intrusion detection systems configured with signatures for known buffer overflow exploitation attempts can provide an additional layer of defense by alerting security teams to suspicious activity targeting these services. Regular auditing of job schedules and monitoring for anomalous process execution patterns will also aid in early detection of any successful exploitation attempts.