CVE-2026-17097 in PowerVM Hypervisor
Summary
by MITRE • 08/19/2026
IBM PowerVM Hypervisor FW1120.00, FW1110.00 through FW1110.30, FW1060.00 through FW1060.80, and FW950.00 through FW950.H2 is affected by a vulnerability in the PowerVM hypervisor call interface. An attacker with root access to a guest partition can issue a specially crafted hypervisor call causing a virtual processor to become permanently unresponsive, requiring a full platform re-IPL to restore normal operation. In some cases this may also cause the guest to inject a small amount of data into hypervisor or partition memory with no attacker control over the target location. Successful exploitation results in an integrity and availability impact to the managed system.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 08/20/2026
The vulnerability identified within IBM PowerVM Hypervisor firmware versions FW1120.00, FW1110.00 through FW1110.30, FW1060.00 through FW1060.80, and FW950.00 through FW950.H2 represents a critical failure in the isolation mechanisms of the hypervisor call interface. This flaw allows an attacker who has already achieved root access within a guest partition to execute specially crafted instructions that interact directly with the underlying virtualization layer. The core technical issue lies in the improper validation or handling of specific hypercalls, which are system calls used by operating systems to request services from the hypervisor. When these malformed requests are processed, they trigger an internal state corruption within the PowerVM environment rather than being safely rejected or handled gracefully. This lack of robust input sanitization at the boundary between guest OS and hypervisor constitutes a significant breach in virtualization security principles, allowing lateral movement from a compromised user-space application to critical infrastructure components.
The operational impact of this vulnerability is severe due to its effect on system availability and integrity. Upon exploitation, the attack causes a specific virtual processor within the managed hardware partition to become permanently unresponsive. This state effectively halts processing capabilities for that core, leading to degraded performance or complete service failure depending on the role of the affected processor. More critically, restoring normal operation requires a full platform re-IPL (Initial Program Load), which is equivalent to a hard reboot of the entire physical server. This requirement introduces substantial downtime and operational disruption, as all partitions running on that hardware must be restarted manually by an administrator or automated recovery system. The necessity for such a drastic measure underscores the severity of the internal state corruption caused by the malicious hypercall, highlighting how guest-level actions can destabilize the foundational infrastructure layer.
Beyond availability issues, there is evidence suggesting potential integrity impacts through memory manipulation capabilities. In certain scenarios, successful exploitation may allow the attacker to inject small amounts of data into hypervisor or partition memory without control over the target location. This behavior indicates a lack of proper bounds checking and access controls when writing to privileged memory regions via hypercalls. While the inability to specify exact write locations limits some forms of precise code injection attacks, it still poses risks related to data corruption and potential privilege escalation vectors if subsequent exploitation chains can leverage this uncontrolled write capability. The unpredictability of where data is written makes forensic analysis difficult and increases the likelihood of cascading failures across other partitions or hypervisor processes sharing that memory space.
From a classification perspective, this vulnerability aligns with CWE-787: Out-of-bounds Write, as it involves writing to memory locations outside intended boundaries due to insufficient validation. It also relates to CWE-20: Improper Input Validation, specifically regarding the failure to sanitize hypercall parameters before processing them at the hypervisor level. In terms of attack tactics, this aligns with MITRE ATT&CK technique T1499: Endpoint Denial of Service, as the primary observable effect is rendering system resources unavailable through processor unresponsiveness and requiring manual intervention for recovery. Additionally, aspects of memory injection may relate to T1055: Process Injection or T1608: Stage Capabilities if used in conjunction with other exploits to establish persistence or further compromise.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. The primary defense is the application of vendor-provided firmware updates that patch the hypercall interface validation logic. Organizations should prioritize updating all affected PowerVM hypervisor versions as soon as patches are available from IBM support channels. In environments where immediate patching is not feasible, strict network segmentation and access controls limiting root-level privileges within guest partitions can reduce the attack surface by preventing unauthorized users or compromised applications from issuing privileged hypercalls. Implementing robust monitoring for anomalous system calls and processor states may also aid in early detection of exploitation attempts before full system failure occurs. Regular audits of partition configurations and enforcement of least-privilege principles are essential to minimize the risk of root compromise leading to hypervisor-level attacks.