Double Free in Alsa-Project Alsa-Lib
CVE-2026-56109
The Advanced Linux Sound Architecture (ALSA) library before 1.2.16.1 contains a double-free vulnerability in parse_def() in src/conf.c that allows attackers to corrupt memory by supplying maliciously crafted ALSA configuration text. When parsing nested compound or array configuration blocks, parse_def() fails to check return values before continuing, causing snd_config_delete() to be called twice on the same already-freed node, resulting in a NULL-pointer write or invalid memory read.
Vulnerability class: Double Free
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H.
EPSS exploit prediction
EPSS: 0.002 (7.3th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 7th percentile — 7.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.000
Affected products
- Alsa-Project Alsa-Lib — versions 0
Weakness classification (CWE)
References
- lore.kernel.org/alsa-devel/CAGt8pqBU0p2voB+qHxWGcNJrKHAcBhAyHUUBPLBN-Yj_SiV6MQ@… (technical-description, exploit)
- github.com/alsa-project/alsa-lib/releases/tag/v1.2.16.1 (release-notes)
- github.com/alsa-project/alsa-lib/commit/536dd6f8affdf5197c12a63a71c92a70b2833cc0 (patch)
- www.vulncheck.com/advisories/alsa-library-double-free-via-parse-def-in-conf-c (third-party-advisory)
Frequently asked questions
- What is CVE-2026-56109?
- CVE-2026-56109 is a medium-severity vulnerability in Alsa-Project Alsa-Lib, classified under Double Free. CVSS score: 6.8/10. Published 2026-06-22.
- How severe is CVE-2026-56109?
- Medium severity. CVSS v3 base score is 6.8 out of 10.