CVE-2025-0986 is a vulnerability identified in IBM PowerVM Hypervisor versions FW1050.00 through FW1050.30 and FW1060.00 through FW1060.20. The flaw relates to improper handling of highly compressed data, specifically involving gzip compression accelerated by hardware under certain Linux processor compatibility mode configurations. This vulnerability is categorized under CWE-409, which concerns improper handling of data amplification scenarios. The issue allows a local user to cause undetected data loss or errors during compression operations. The vulnerability arises because the hypervisor's hardware-accelerated gzip compression does not correctly manage edge cases in data processing, leading to potential silent corruption or loss of data. The CVSS v3.1 base score is 4.5, indicating a medium severity level. The vector shows that exploitation requires local access (AV:L), high attack complexity (AC:H), no privileges (PR:N), no user interaction (UI:N), and the scope is changed (S:C), with no impact on confidentiality but limited impact on integrity and availability. No known exploits are currently reported in the wild, and no patches are linked yet. This vulnerability could affect environments where IBM PowerVM Hypervisor is used to run Linux workloads with hardware-accelerated gzip compression enabled, particularly in configurations involving processor compatibility modes that trigger this flaw. The silent nature of data loss or errors poses a risk to data integrity and reliability of compressed data storage or transmission within virtualized environments.

For European organizations using IBM PowerVM Hypervisor, particularly those running Linux workloads with hardware-accelerated gzip compression enabled, this vulnerability could lead to silent data corruption or loss. This can undermine data integrity, potentially affecting critical applications relying on compressed data for storage or communication. Industries such as finance, telecommunications, and government sectors, which often use IBM PowerVM for virtualization, may face operational disruptions or data reliability issues. Although the vulnerability requires local access and has high attack complexity, insider threats or compromised internal systems could exploit it. The undetected nature of the data loss complicates detection and forensic analysis, increasing risk to data-driven decision-making and compliance with data integrity regulations such as GDPR. However, the absence of confidentiality impact reduces the risk of data leakage. The medium severity rating suggests a moderate but non-trivial risk, especially in environments with high data compression workloads and strict data integrity requirements.

European organizations should first identify if their IBM PowerVM Hypervisor deployments are running affected versions (FW1050.00 through FW1050.30 and FW1060.00 through FW1060.20) and if hardware-accelerated gzip compression is enabled under Linux processor compatibility modes. Until official patches are released, organizations should consider disabling hardware acceleration for gzip compression in affected environments to prevent triggering the vulnerability. Implement strict access controls and monitoring to limit local user access, reducing the risk of exploitation. Conduct integrity checks and validation on compressed data outputs to detect anomalies early. Establish logging and alerting mechanisms for compression-related errors. Engage with IBM support for updates on patches or workarounds. Additionally, review and tighten insider threat detection capabilities, as exploitation requires local access. For critical systems, consider isolating vulnerable hypervisor instances or migrating workloads to unaffected platforms or versions. Finally, maintain regular backups of critical data to mitigate potential data loss consequences.