CVE-2026-17591: Use After Free in Red Hat Red Hat Enterprise Linux 10

A use-after-free vulnerability exists in libarchive's archive_entry_copy_mac_metadata() function in Red Hat Enterprise Linux 10. The function deallocates an internal buffer before completing a data copy, allowing an attacker who can supply input to an application using this function to cause a crash or read uninitialized memory. The issue can result in Denial of Service or limited information disclosure. The vulnerability has a CVSS 3.1 base score of 3.6, with attack vector local, high attack complexity, no privileges required, and requires user interaction.

An attacker with local access who can provide input to an application using the vulnerable function may cause the application to crash (Denial of Service) or potentially read uninitialized memory, leading to limited information disclosure. The impact on confidentiality is low, integrity is not affected, and availability impact is low due to possible application crashes.

Patch status is not yet confirmed — check the Red Hat advisory at https://access.redhat.com/security/cve/CVE-2026-17591 for current remediation guidance. Until a patch is applied, restrict local access to trusted users and avoid running untrusted input through applications using libarchive's archive_entry_copy_mac_metadata() function.