CVE-2026-56109: ALSA alsa-lib double free in parse_def configuration parser

CVE-2026-56109 · Severity: medium · CVSS 6.8 · Published 2026-06-22

The Advanced Linux Sound Architecture (ALSA) library, a standard component for sound support in Linux systems, contains a memory management flaw. An attacker can exploit this by providing a specially crafted configuration file (such as a user-level .asoundrc file), which causes applications using the library to crash or potentially allow for further system compromise. This impact is particularly relevant for systems where users can influence audio configuration settings.

Technologies: ALSA Project Alsa-Lib. Vendors: ALSA Project.

Quick answers

Is CVE-2026-56109 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-56109 being exploited in the wild.
How severe is CVE-2026-56109?
Medium severity, with a CVSS score of 6.8, published 22 June 2026.
Which products and versions are affected?
ALSA Project Alsa-Lib < 1.2.16.1.
Is there a fix for CVE-2026-56109?
A patch was published on 2026-06-14: Version 1.2.16.1 released with fix Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-56109 attacked?
It is attacked with local access, in a software library.
Am I affected by CVE-2026-56109?
Check whether you run ALSA Project Alsa-Lib at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A double-free vulnerability exists in the `parse_def()` function within `src/conf.c` of alsa-lib. The root cause is a failure to check the return values of recursive calls to `parse_defs()` or `parse_array_defs()` when processing nested compound or array configuration blocks. If a nested call fails and deletes a configuration node, `parse_def()` incorrectly proceeds to call `snd_config_delete()` on the same node during its own error handling path. This results in a double-free, manifesting as either a NULL-pointer write in `list_del()` or an invalid memory read. The vulnerability is reachable via public APIs such as `snd_config_load_string()` and is fixed in version 1.2.16.1.

Affected products

  • alsa-project alsa-lib < 1.2.16.1

Timeline

  • 2026-06-08: disclosed: Vulnerability reported to ALSA maintainers by Luigino Camastra
  • 2026-06-14: patched: Version 1.2.16.1 released with fix
  • 2026-06-22: advisory: CVE-2026-56109 published

References

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