CVE-2025-27087 is a vulnerability identified in the kernel of the Hewlett Packard Enterprise (HPE) Cray Operating System (COS), which is a specialized operating system used primarily in high-performance computing (HPC) environments. The vulnerability allows a local attacker with limited privileges (low privileges) to trigger a Denial of Service (DoS) condition by exploiting a resource exhaustion issue classified under CWE-400 (Uncontrolled Resource Consumption). Specifically, the flaw resides in the kernel, which is the core component of the operating system responsible for managing system resources and hardware interactions. An attacker who has local access to the system can exploit this vulnerability to cause the system to become unresponsive or crash, thereby disrupting availability. The CVSS v3.1 base score is 5.5, indicating a medium severity level. The attack vector is local (AV:L), meaning remote exploitation is not possible without prior access. The attack complexity is low (AC:L), and it requires low privileges (PR:L) but no user interaction (UI:N). The scope is unchanged (S:U), and the impact is solely on availability (A:H) with no confidentiality or integrity impact. No known exploits are currently in the wild, and no patches have been published at the time of this analysis. The vulnerability was reserved in February 2025 and published in April 2025. Given the nature of the HPE Cray COS, this vulnerability primarily affects HPC systems used in research institutions, government labs, and enterprises relying on supercomputing capabilities.

For European organizations, the impact of CVE-2025-27087 is primarily on the availability of critical HPC infrastructure. Organizations that rely on HPE Cray COS for scientific research, weather modeling, energy simulations, or defense-related computations could face operational disruptions if this vulnerability is exploited. A successful local DoS attack could halt ongoing computations, delay project timelines, and potentially cause data loss if systems crash unexpectedly. While the vulnerability does not directly compromise confidentiality or integrity, the loss of availability in HPC environments can have significant downstream effects, including financial losses and reputational damage. The requirement for local access limits the attack surface, but insider threats or compromised user accounts could be leveraged to exploit this vulnerability. European research centers, universities, and government agencies with HPC clusters running HPE Cray COS are particularly at risk. The absence of known exploits reduces immediate risk, but the medium severity score suggests that organizations should proactively address this issue to maintain operational continuity.

Given the lack of an official patch at the time of this report, European organizations should implement several practical mitigations: 1) Restrict local access strictly to trusted personnel and enforce strong access controls and monitoring on HPC systems running HPE Cray COS. 2) Employ robust user account management, including multi-factor authentication and least privilege principles, to minimize the risk of privilege escalation or misuse. 3) Monitor system logs and kernel behavior for unusual resource consumption patterns that could indicate attempts to exploit the vulnerability. 4) Isolate HPC environments from general-purpose networks to reduce the risk of lateral movement by attackers. 5) Engage with HPE support and subscribe to security advisories to obtain patches or workarounds as soon as they become available. 6) Consider implementing resource limits or kernel-level protections that can mitigate resource exhaustion attacks, such as cgroups or similar mechanisms if supported by the OS. 7) Conduct regular security audits and penetration tests focusing on local privilege abuse scenarios to identify potential exploitation paths. These targeted measures go beyond generic advice by focusing on the unique operational context of HPC systems and the specific characteristics of this vulnerability.