CVE-2026-17414 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 Power Systems Firmware is affected by a vulnerability in partition firmware during network boot. An unauthenticated attacker with access to the same network as a partition performing a network boot can prevent that partition from completing its boot sequence. On partitions where OS secure boot is not enabled, which is the default configuration, the attacker can also substitute the boot image, compromising everything subsequently loaded by that partition. Other partitions and the managed system are not affected. Only partitions actively performing a network boot are affected, resulting in a confidentiality, integrity, and availability impact.
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Analysis
by VulDB Data Team • 08/19/2026
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 security flaw in the partition firmware's handling of network boot processes. This issue specifically targets systems configured to perform Preboot Execution Environment or similar network-based initialization procedures. The core technical deficiency lies in the lack of authentication and integrity verification mechanisms during the initial stages of loading the operating system image from a remote server over the network. Because the firmware does not cryptographically validate the source or content of the boot images before execution, it remains susceptible to interception and manipulation by any actor with access to the same local area network segment as the partition undergoing the boot sequence. This architectural oversight allows an unauthenticated attacker positioned on the network path to interact directly with the boot protocol exchanges, effectively bypassing standard security controls that would otherwise protect against such tampering.
From a technical perspective, this vulnerability enables two distinct attack vectors depending on the system's configuration regarding secure boot capabilities. In scenarios where OS secure boot is disabled, which constitutes the default configuration for many IBM Power Systems deployments, an attacker can substitute the legitimate boot image with a malicious alternative. This substitution allows the compromised partition to load and execute arbitrary code under the guise of a valid operating system or bootloader. The implications are severe, as this action compromises the integrity of all subsequent software loaded by that partition, potentially leading to full system compromise, data exfiltration, or the establishment of persistent backdoors within the guest environment. Even in configurations where secure boot is enabled, the attacker retains the ability to disrupt the process entirely by preventing the completion of the boot sequence, thereby denying access to the resources hosted on that specific partition.
The operational impact of this vulnerability extends primarily to confidentiality, integrity, and availability for the affected partitions, while leaving other partitions and the managed system itself unaffected due to isolation boundaries inherent in virtualization architectures. The denial-of-service aspect is particularly relevant for environments relying heavily on automated provisioning or remote management workflows where network booting is a standard procedure. An attacker can effectively take specific logical systems offline by interrupting their initialization process, causing service disruptions without needing to exploit deeper kernel-level vulnerabilities. For organizations utilizing these firmware versions in production environments with secure boot disabled, the risk profile escalates significantly as it allows for silent compromise of system integrity and potential lateral movement if the compromised partition is trusted within a broader network topology.
To mitigate this risk, administrators must prioritize enabling OS secure boot on all affected partitions to enforce cryptographic verification of boot components before execution occurs. This measure ensures that only signed and authorized images are loaded, neutralizing the ability of an attacker to substitute malicious code even if they intercept the network traffic during the boot phase. Additionally, implementing network-level security controls such as IPsec for boot protocols or restricting access to PXE servers via VLAN segmentation can reduce the attack surface by limiting which hosts can respond to boot requests. Regularly updating firmware to versions that address these specific flaws is also essential, although immediate mitigation through configuration changes remains critical given the widespread default settings. Organizations should audit their network architecture to ensure that management and provisioning networks are isolated from general user traffic to prevent unauthorized entities from positioning themselves on the same broadcast domain as vulnerable partitions.
This vulnerability aligns with Common Weakness Enumeration categories such as CWE-287, which describes Improper Authentication, specifically regarding the failure of the firmware to verify the identity or integrity of external boot sources before accepting them for execution. It also relates closely to CWE-345, Insufficient Verification of Data Authenticity, as the system fails to validate that the received data matches its expected state from a trusted source. In terms of adversarial tactics, this flaw facilitates techniques associated with MITRE ATT&CK ID T1072, Software Deployment Tools, where attackers use legitimate tools or protocols for lateral movement and execution, although in this case, it is more directly related to initial access via compromised boot processes akin to T1583.004, Acquire Infrastructure: Virtual Private Server, if the attacker provisions a rogue DHCP/TFTP server on the network. The exploitation of this flaw allows an adversary to establish a foothold within the virtualized environment without triggering traditional endpoint detection mechanisms that monitor runtime behavior rather than pre-boot initialization sequences.