CVE-2026-41066

7.5

HIGH CVSS 3.1

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

Overview

Description

lxml is a library for processing XML and HTML in the Python language. Prior to 6.1.0, using either of the two parsers in the default configuration (with resolve_entities=True) allows untrusted XML input to read local files. Setting the resolve_entities option explicitly to resolve_entities='internal' or resolve_entities=False disables the local file access. This vulnerability is fixed in 6.1.0.

Details

INFO

Published Date :

April 24, 2026, 5:16 p.m.

Last Modified :

April 27, 2026, 5:59 p.m.

Remotely Exploit :

Yes !

Source :

[email protected]

Impact

Affected Products

The following products are affected by CVE-2026-41066 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID	Vendor	Product	Action
1	Lxml	lxml

: Total Affected Vendor : 1 | Products : 1

Scoring

CVSS Scores

The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.

Score	Version	Severity	Vector	Exploitability Score	Impact Score	Source
	CVSS 3.1	HIGH				[email protected]

Solution

Update lxml to version 6.1.0 or later to fix XML entity resolution.

Update the lxml library to version 6.1.0.
Disable local file access by setting resolve_entities to 'internal' or False.

Public PoC/Exploit Available at Github

CVE-2026-41066 has a 5 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

References

References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-41066.

URL	Resource
https://bugs.launchpad.net/lxml/+bug/2146291	Exploit Issue Tracking Third Party Advisory
https://github.com/lxml/lxml/security/advisories/GHSA-vfmq-68hx-4jfw	Mitigation Vendor Advisory

CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-41066 is associated with the following CWEs:

CWE-611: Improper Restriction of XML External Entity Reference

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-41066 weaknesses.

CAPEC-221: Data Serialization External Entities Blowup Data Serialization External Entities Blowup

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Semicolon2026/work_init_power

None

Dockerfile Shell Python

Updated: 1 week, 5 days ago

0 stars 0 fork 0 watcher

Born at : May 16, 2026, 6:20 a.m. This repo has been linked 2 different CVEs too.

StandFast1/forum

None

Dockerfile Python HTML PowerShell

Updated: 1 month ago

1 stars 0 fork 0 watcher

Born at : March 16, 2026, 3:16 p.m. This repo has been linked 4 different CVEs too.

Nubaeon/empirica

Make AI agents and AI workflows measurably reliable. Epistemic measurement, Noetic RAG, Sentinel gating, and grounded calibration for Claude Code and beyond

ai-agents ai-workflows ai-memory ai-os epistemic-ai anti-confabulation

Makefile Python Shell Dockerfile PowerShell Ruby

Updated: 1 month ago

213 stars 25 fork 25 watcher

Born at : Nov. 1, 2025, 4:08 p.m. This repo has been linked 3 different CVEs too.

prefect421/mvidarr

MVidarr - The Music Video Management System

HTML Python Shell JavaScript CSS TypeScript Batchfile Dockerfile Mako Go Template

Updated: 2 weeks, 3 days ago

40 stars 1 fork 1 watcher

Born at : July 24, 2025, 1:49 a.m. This repo has been linked 6 different CVEs too.

runwhen-contrib/helm-charts

All Public RunWhen Helm Charts - Managed by terraform

Shell Dockerfile Go Template

Updated: 1 day, 23 hours ago

1 stars 0 fork 0 watcher

Born at : Sept. 18, 2023, 10:09 a.m. This repo has been linked 115 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-41066 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-41066 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

Initial Analysis by [email protected]

Apr. 27, 2026

Action	Type	New Value
Added	CPE Configuration	OR cpe:2.3:a:lxml:lxml::::::::* versions up to (excluding) 6.1.0
Added	Reference Type	GitHub, Inc.: https://bugs.launchpad.net/lxml/+bug/2146291 Types: Exploit, Issue Tracking, Third Party Advisory
Added	Reference Type	GitHub, Inc.: https://github.com/lxml/lxml/security/advisories/GHSA-vfmq-68hx-4jfw Types: Mitigation, Vendor Advisory

New CVE Received by [email protected]

Apr. 24, 2026

Action	Type	New Value
Added	Description	lxml is a library for processing XML and HTML in the Python language. Prior to 6.1.0, using either of the two parsers in the default configuration (with resolve_entities=True) allows untrusted XML input to read local files. Setting the resolve_entities option explicitly to resolve_entities='internal' or resolve_entities=False disables the local file access. This vulnerability is fixed in 6.1.0.
Added	CVSS V3.1	AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Added	CWE	CWE-611
Added	Reference	https://bugs.launchpad.net/lxml/+bug/2146291
Added	Reference	https://github.com/lxml/lxml/security/advisories/GHSA-vfmq-68hx-4jfw

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.