CVE-2025-5916 is a vulnerability in the libarchive library, a widely used open-source library for reading and writing various archive formats. The flaw is an integer overflow or wraparound triggered when libarchive processes a Web Archive (WARC) file that falsely claims to contain more than INT64_MAX - 4 content bytes. This integer overflow can cause the internal size calculations to wrap around, leading to memory corruption or unpredictable program behavior. Such behavior can result in denial-of-service (DoS) conditions or potentially other undefined behaviors depending on how the corrupted memory is used. The vulnerability affects all libarchive versions prior to 3.8.0, including those shipped with Red Hat Enterprise Linux 10. Exploitation requires local privileges and user interaction, as the attacker must supply a crafted WARC file to an application that uses libarchive for processing. The CVSS 3.1 base score is 3.9, reflecting low severity due to limited impact on confidentiality and integrity, and the requirement for local access and user interaction. No known exploits have been reported in the wild, but the vulnerability poses a risk to any application that processes untrusted WARC files using vulnerable libarchive versions. The flaw is particularly relevant for organizations handling large-scale web archives or digital preservation systems that rely on libarchive.

For European organizations, the primary impact is potential denial-of-service or application crashes in systems that process WARC files using vulnerable libarchive versions. This could disrupt services that rely on archive processing, such as digital libraries, web archiving institutions, or data analytics platforms handling archived web content. Memory corruption could theoretically lead to further instability or exploitation, but given the low CVSS score and lack of known exploits, the immediate risk is limited. Confidentiality and integrity impacts are minimal since the flaw does not directly enable data leakage or unauthorized modification. However, availability could be affected if critical systems crash or become unresponsive. Organizations using Red Hat Enterprise Linux 10 or other Linux distributions bundling vulnerable libarchive versions should prioritize patching to avoid service disruptions. The threat is lower for organizations that do not process WARC files or do so in controlled environments with trusted data.

1. Upgrade libarchive to version 3.8.0 or later, where the integer overflow vulnerability is fixed. 2. Apply all relevant security updates provided by Linux distribution vendors, especially Red Hat for RHEL 10. 3. Implement strict input validation and size checks on WARC files before processing to detect and reject files with suspiciously large declared content sizes. 4. Restrict processing of WARC files to trusted sources and environments to reduce exposure to crafted malicious archives. 5. Employ sandboxing or containerization for applications that handle archive files to limit the impact of potential crashes or memory corruption. 6. Monitor application logs and system behavior for signs of crashes or abnormal terminations related to archive processing. 7. Educate users and administrators about the risks of processing untrusted archive files and the importance of applying patches promptly.