CVE-2025-5916 is a vulnerability identified in the libarchive library, specifically triggered when processing Web Archive (WARC) files that claim to contain more than INT64_MAX - 4 content bytes. This integer overflow or wraparound occurs because the library does not properly validate or handle extremely large size fields in the WARC format, leading to an arithmetic overflow during size calculations. When exploited, this can cause unpredictable program behavior such as memory corruption or denial-of-service (DoS) conditions in applications that rely on libarchive for archive extraction or processing. The vulnerability requires local access with low privileges and some user interaction, as indicated by the CVSS vector (AV:L/PR:L/UI:R). The impact on confidentiality and integrity is low, but availability can be affected due to potential crashes or resource exhaustion. The vulnerability affects Red Hat Enterprise Linux 10 and potentially other systems using vulnerable versions of libarchive. No public exploits are known at this time, but the flaw could be leveraged by attackers to disrupt services or cause application instability. The vulnerability was published on June 9, 2025, and currently lacks a vendor patch link, indicating that remediation may still be pending or in progress. Organizations processing WARC files, especially in environments where libarchive is used extensively, should prioritize risk assessment and mitigation.

For European organizations, the primary impact of CVE-2025-5916 lies in potential denial-of-service conditions or application crashes when processing maliciously crafted WARC files. This can disrupt services that rely on archival data extraction or processing, such as digital libraries, research institutions, media companies, and governmental archives. Although the confidentiality and integrity impact is low, availability disruptions can affect business continuity and operational reliability. Organizations using Red Hat Enterprise Linux 10 or other Linux distributions with vulnerable libarchive versions are at risk. The requirement for local access and user interaction limits remote exploitation, reducing the likelihood of widespread automated attacks. However, insider threats or compromised user accounts could exploit this vulnerability to cause targeted disruptions. The lack of known exploits in the wild currently lowers immediate risk but does not eliminate the potential for future exploitation. European entities with critical infrastructure or regulatory requirements for data availability should consider this vulnerability significant enough to warrant prompt mitigation.

1. Apply vendor patches promptly once they become available from Red Hat or other distributors to address the integer overflow in libarchive. 2. Restrict processing of untrusted or unauthenticated WARC files, especially from external or unknown sources, to reduce exposure to crafted malicious archives. 3. Implement strict access controls and user privilege management to limit local user capabilities, minimizing the risk of exploitation requiring low privileges. 4. Monitor application and system logs for abnormal crashes, memory errors, or denial-of-service symptoms related to archive processing. 5. Consider sandboxing or isolating archive processing components to contain potential impacts of exploitation. 6. Educate users about the risks of interacting with untrusted archive files and enforce policies to prevent inadvertent processing of suspicious WARC files. 7. Conduct regular security assessments and vulnerability scans to detect outdated libarchive versions and ensure timely updates. 8. If immediate patching is not possible, consider disabling WARC file processing features or replacing libarchive with alternative libraries that are not vulnerable.