Vulnerability in alsa-lib (UBUNTU-CVE-2026-56109)

Summary

Vulnerability in alsa-lib (UBUNTU-CVE-2026-56109). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 1.2.6.1-1ubuntu1.2 or later.

Original description

The description as published by the source.

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.

Source: OSV.dev (Open Source Vulnerabilities) OSV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as UBUNTU-CVE-2026-56109 has been found in alsa-lib.
Risk of unauthorized operations or information disclosure.
What to do: upgrade alsa-lib to 1.2.6.1-1ubuntu1.2 or later.
If unsure, ask your IT team or search "alsa-lib UBUNTU-CVE-2026-56109" on the vendor's site.

UBUNTU-CVE-2026-56109 (alsa-lib)
Attack vector: local / unauthenticated / no user interaction
Patched: 1.2.6.1-1ubuntu1.2 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (unclassified) exists in alsa-lib.

📍 Affected scope

Check the vendor advisory for the affected versions of alsa-lib.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 1.2.6.1-1ubuntu1.2.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'alsa-lib' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
grep -r 'alsa-lib' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で alsa-lib を grep し、稼働しているサービス・バージョンを把握する。
2
Apply patch patch
```
Upgrade alsa-lib to 1.2.6.1-1ubuntu1.2
```
ステージング環境で 1.2.6.1-1ubuntu1.2 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
3
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。