CVE-2025-5915 is a heap-based buffer overflow vulnerability identified in the libarchive library, which is widely used for handling archive files across many Linux distributions, including Red Hat Enterprise Linux 10. The vulnerability occurs when the size of a filter block processed by the library exceeds the size of the Lempel-Ziv-Storer-Schieber (LZSS) decompression window. This condition causes the library to perform a heap buffer over-read, reading memory beyond the allocated buffer boundaries. Such out-of-bounds reads can lead to unpredictable application behavior, including crashes (denial of service) or the unintended disclosure of sensitive information residing in adjacent heap memory. The vulnerability requires local access with low privileges and user interaction to trigger, indicating that an attacker must have some level of access and induce the vulnerable code path, for example, by processing a crafted archive file. The CVSS v3.1 score is 6.6, reflecting medium severity, with a vector indicating local attack vector, low attack complexity, low privileges required, and user interaction needed. The impact primarily affects confidentiality and availability, with no direct integrity compromise. No public exploits are known at this time, but the vulnerability is published and should be addressed promptly. The affected product is Red Hat Enterprise Linux 10, but since libarchive is common in many Linux environments, other distributions may also be at risk if they use vulnerable versions of the library.

The vulnerability can cause denial of service through application crashes when processing maliciously crafted archive files, disrupting services that rely on libarchive for file extraction or compression. More critically, the heap buffer over-read can lead to the exposure of sensitive information from adjacent memory regions, potentially leaking data such as cryptographic keys, passwords, or other confidential information. Since exploitation requires local privileges and user interaction, remote exploitation is unlikely without prior access. However, in multi-user or shared environments, an attacker with limited privileges could escalate information disclosure risks. Organizations running Red Hat Enterprise Linux 10 or other systems using vulnerable libarchive versions may face operational disruptions and data confidentiality risks. This is particularly concerning for servers handling untrusted archive files or automated processing pipelines. The absence of known exploits reduces immediate risk but does not eliminate the potential for future attacks.

Organizations should monitor Red Hat and libarchive project advisories for patches addressing CVE-2025-5915 and apply updates promptly once available. Until patches are deployed, restrict local user permissions to limit who can execute or trigger archive processing functions. Implement strict file validation and scanning for archive files, especially those received from untrusted sources, to prevent malicious payloads. Employ application whitelisting and sandboxing techniques to isolate processes handling archive files, reducing the impact of potential crashes or data leaks. Regularly audit systems for unusual crashes or memory access errors related to archive processing. Consider disabling or limiting the use of libarchive in environments where it is not essential. Additionally, educate users about the risks of opening untrusted archive files and require user interaction confirmation before processing such files.