CVE-2025-5918 is a security vulnerability identified in the libarchive library, which is widely used for handling archive files in Unix-like operating systems. The vulnerability specifically affects the bsdtar utility, a tool that extracts and creates archive files. The flaw is an out-of-bounds read that occurs when file streams are piped into bsdtar, causing the program to read data beyond the end of the file buffer. This improper memory access can lead to unpredictable program behavior, including memory corruption and denial-of-service (DoS) conditions. The vulnerability requires local access with low privileges and user interaction, such as executing a crafted command that pipes malicious file streams into bsdtar. The CVSS 3.1 score of 3.9 reflects a low severity rating, primarily due to the limited impact on confidentiality and integrity, and the requirement for local privileges and user interaction. The affected product is Red Hat Enterprise Linux 10, which bundles libarchive and bsdtar. No public exploits have been reported, and no patches or mitigation links are currently provided, indicating that the vulnerability is newly disclosed. The risk mainly involves potential service disruption or application crashes rather than data breaches or privilege escalation.

For European organizations, the primary impact of CVE-2025-5918 lies in potential denial-of-service conditions caused by memory corruption or crashes of bsdtar when processing maliciously crafted archive streams. This can disrupt automated backup, deployment, or archival processes that rely on bsdtar, potentially affecting business continuity. Confidentiality and integrity impacts are minimal since the vulnerability does not allow for arbitrary code execution or data modification. However, organizations with critical systems that use Red Hat Enterprise Linux 10 and depend on bsdtar for file extraction or archival tasks may experience operational interruptions. The requirement for local privileges and user interaction limits remote exploitation, reducing the risk of widespread attacks. Nonetheless, insider threats or compromised local accounts could exploit this vulnerability to cause service outages. The absence of known exploits in the wild suggests limited immediate risk, but the vulnerability should be addressed proactively to maintain system stability and reliability.

European organizations should monitor Red Hat advisories for official patches addressing CVE-2025-5918 and apply them promptly once available. Until patches are released, restrict access to systems running Red Hat Enterprise Linux 10 to trusted users only, minimizing the risk of local exploitation. Implement strict input validation and avoid processing untrusted or unauthenticated archive files with bsdtar, especially when using piped file streams. Consider using alternative archive extraction tools that are not affected by this vulnerability for handling untrusted data. Employ system-level protections such as memory protection mechanisms (e.g., ASLR, DEP) to mitigate the impact of out-of-bounds reads. Regularly audit and monitor system logs for unusual crashes or abnormal bsdtar behavior that could indicate exploitation attempts. Incorporate this vulnerability into vulnerability management and incident response plans to ensure timely detection and remediation.