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 manifests as an out-of-bounds read when file streams are piped into the bsdtar utility, a component of libarchive responsible for creating and extracting archive files. An out-of-bounds read occurs when a program reads data beyond the allocated buffer or the end of a file, which can lead to unpredictable program behavior, memory corruption, or denial-of-service (DoS) conditions. In this case, the flaw can be triggered locally by a user with limited privileges (PR:L) and requires user interaction (UI:R), such as executing a crafted command that pipes a malicious or malformed file stream into bsdtar. The CVSS v3.1 base score of 3.9 reflects a low severity rating, primarily because the attack vector is local, requires privileges, and user interaction, and the impact on confidentiality and integrity is minimal (only a low impact on confidentiality and availability). The vulnerability affects Red Hat Enterprise Linux 10, a widely used enterprise Linux distribution, which means that systems running this OS and utilizing bsdtar for archive management are susceptible. While no known exploits are currently in the wild, the potential for memory corruption or DoS means that attackers could disrupt services or cause application crashes if they gain access to vulnerable systems. The vulnerability does not appear to allow privilege escalation or remote code execution directly but could be leveraged as part of a broader attack chain. No patches or mitigation links are provided yet, indicating that this is a recently disclosed issue requiring attention from system administrators and security teams.

For European organizations, the impact of CVE-2025-5918 is primarily related to potential denial-of-service conditions or application instability caused by memory corruption when using bsdtar on Red Hat Enterprise Linux 10 systems. Organizations relying on automated archive processing, backup systems, or software deployment pipelines that utilize bsdtar could experience service interruptions or crashes if the vulnerability is exploited. Although the confidentiality and integrity impacts are low, availability disruptions could affect critical business operations, especially in sectors such as finance, healthcare, and government where Red Hat Enterprise Linux is prevalent. The requirement for local privileges and user interaction limits the attack surface, reducing the likelihood of widespread exploitation. However, insider threats or compromised user accounts could still leverage this vulnerability to disrupt services. The absence of known exploits reduces immediate risk but does not eliminate the need for proactive mitigation. Overall, the impact is moderate for organizations with high dependency on affected systems and processes.

1. Monitor Red Hat and libarchive project announcements closely for official patches addressing CVE-2025-5918 and apply them promptly once available. 2. Restrict access to bsdtar and related utilities to trusted users only, minimizing the risk of exploitation by unprivileged or malicious users. 3. Implement strict user privilege management and auditing to detect and prevent unauthorized execution of archive processing commands. 4. Use application whitelisting or endpoint protection solutions to monitor and control execution of bsdtar and related processes. 5. In environments with automated archive handling, introduce input validation and integrity checks on files before processing to reduce the risk of malformed streams triggering the vulnerability. 6. Consider isolating archive processing tasks in sandboxed or containerized environments to limit the impact of potential crashes or memory corruption. 7. Maintain comprehensive logging and alerting on system errors or crashes related to bsdtar to enable rapid detection of exploitation attempts. 8. Educate users and administrators about the risks of executing untrusted archive files and the importance of following security best practices.