CVE-2026-56109 describes a double-free vulnerability in the ALSA library's parse_def() function. When processing nested configuration blocks, the library attempts to free an already freed memory node, leading to memory corruption. This can cause system instability, crashes, or denial of service. The vulnerability affects ALSA library versions prior to 1.2.16.1-2.hum1 as included in Red Hat Hardened Images RPMs. Red Hat has released updated RPMs (alsa-lib-1.2.16.1-2.hum1 and related packages) as part of a bug fix and enhancement update. However, the vendor advisory states that no direct fix is currently available or that available mitigations do not meet Red Hat's criteria for ease of use and deployment. The CVSS base score from Red Hat is 6.8 (medium severity), with an attack vector of local, low complexity, no privileges required, and no user interaction needed. The impact includes potential denial of service due to crashes from memory corruption.

The vulnerability allows a local attacker to corrupt memory by triggering a double-free condition in the ALSA library, which can lead to system instability, crashes, or denial of service. There is no indication of confidentiality or privilege escalation impact. The flaw is exploitable locally without privileges or user interaction. Red Hat rates the impact as medium severity with a CVSS score of 6.8, primarily due to the availability impact (denial of service). No known exploits in the wild have been reported.

Red Hat has released updated RPM packages for Red Hat Hardened Images including alsa-lib-1.2.16.1-2.hum1 and related components. Users should apply these updates as per Red Hat's guidance available at https://images.redhat.com/. Currently, no alternative mitigation is available or recommended by Red Hat that meets their criteria for ease of deployment and applicability. Users should monitor Red Hat advisories for any future fixes or mitigations. No urgent action beyond applying the update is indicated.