What is GHSA-vfmq-68hx-4jfw?

GHSA-vfmq-68hx-4jfw is a security advisory published by GitHub Security Advisories with High severity. lxml: Default configuration of iterparse() and ETCompatXMLParser() allows XXE to local files

Which CVE IDs does GHSA-vfmq-68hx-4jfw cover?

GHSA-vfmq-68hx-4jfw covers the following CVE IDs: CVE-2026-41066. Each CVE has its own detail page on EchelonGraph Pulse with the synthesized EG score.

What is the CVSS v3 score of GHSA-vfmq-68hx-4jfw?

GHSA-vfmq-68hx-4jfw has a CVSS v3 base score of 7.5, published by GitHub Security Advisories.

Which products are affected by GHSA-vfmq-68hx-4jfw?

GHSA-vfmq-68hx-4jfw affects 1 product, including: pip/lxml:\u003c 6.1.0.

GHSA-vfmq-68hx-4jfwHighCVSS 7.5

lxml: Default configuration of iterparse() and ETCompatXMLParser() allows XXE to local files

Vendor

GitHub Security Advisories

Published

April 21, 2026

Last Modified

June 6, 2026

🔗 CVE IDs covered (1)

CVE-2026-41066 →

📋 Description

Impact

Using either of the two parsers in the default configuration (with resolve_entities=True) allows untrusted XML input to read local files.

Patches

lxml 6.1.0 changes the default to resolve_entities='internal', thus disallowing local file access by default.

Workarounds

Setting the resolve_entities option explicitly to resolve_entities='internal' or resolve_entities=False disables the local file access.

Resources

Original report: https://bugs.launchpad.net/lxml/+bug/2146291

The default option was changed to resolve_entities='internal' for the normal XML and HTML parsers in lxml 5.0. The default was not changed for iterparse() and ETCompatXMLParser() at the time. lxml 6.1 makes the safe option the default for all parsers.

🎯 Affected products1

pip/lxml:< 6.1.0