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Fencer Intel
high 7.5

CVE-2026-41066 json

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

published 6mo ago modified last mo. also EUVD-2026-25572 , GHSA-vfmq-68hx-4jfw , PYSEC-2026-87

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 25%
public exploits
0
none known

Summary

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.

Patch / fix

  • pypi lxml 6.1.0
  • lxml lxml 6.1.0
  • lxml Debian 12 4.9.2-1+deb12u1
  • lxml Debian 14 6.1.0-1

debian advisories DEBIAN-CVE-2026-41066

  • lxml Ubuntu 22.04 LTS 4.8.0-1ubuntu0.1
  • lxml Ubuntu 24.04 LTS 5.2.1-1ubuntu0.2
  • lxml Ubuntu 26.04 LTS 6.0.2-1ubuntu0.1
  • lxml Ubuntu Pro 14.04 LTS 3.3.3-1ubuntu0.2+esm6
  • lxml Ubuntu Pro 16.04 LTS 3.5.0-1ubuntu0.4+esm3
  • lxml Ubuntu Pro 18.04 LTS 4.2.1-1ubuntu0.6+esm1
  • lxml Ubuntu Pro 20.04 LTS 4.5.0-1ubuntu0.5+esm1

ubuntu advisories UBUNTU-CVE-2026-41066

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • grafana Multi Linux Manager Tools SLE-15 12.4.10-150002.4.27.1
  • mgr-push Multi Linux Manager Tools SLE-15 5.2.5-150002.3.12.1
  • spacecmd Multi Linux Manager Tools SLE-15 5.2.10-150002.3.15.1
  • uyuni-tools Multi Linux Manager Tools SLE-Micro-5, Multi Linux Manager Tools SLE-15 5.2.17-150002.3.20.1
  • venv-salt-minion Multi Linux Manager Tools SLE-Micro-5, Multi Linux Manager Tools SLE-15 3006.0-150002.5.22.1
  • spacewalk-client-tools Multi Linux Manager Tools SLE-15 5.2.7-150002.3.12.1
  • golang-github-prometheus-prometheus Multi Linux Manager Tools SLE-15 3.13.2-150002.3.19.1
  • mgr-push Multi Linux Manager Tools SLE-12 5.2.5-120002.3.12.1

suse advisories SUSE-SU-2026:4585-1SUSE-SU-2026:4584-1SUSE-SU-2026:4583-1SUSE-SU-2026:4582-1SUSE-SU-2026:4581-1SUSE-SU-2026:4580-1

  • python-lxml openSUSE Tumbleweed 6.1.0-1.1

opensuse advisories openSUSE-SU-2026:10596-1

  • py3-lxml Alpine 3.24 6.1.0-r0

alpine advisories ALPINE-CVE-2026-41066

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • python-lxml Azure Linux 3.0 4.9.3-2

azure linux advisories AZL-84038

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Is CVE-2026-41066 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-41066 updated cvss 5.9

lxml: python: lxml: Information disclosure via untrusted XML input leading to local file read

  • Red Hat Migration Toolkit for Applications 8 mta/mta-solution-server-rhel9 Red Hat Pen Drive Powered by Red Hat Lightspeed pen-drive/pen-drive-scanner-rhel9 Red Hat AI Inference Server rhaiis/vllm-neuron-rhel9 Red Hat Ansible Automation Platform 2 automation-controller, ansible-automation-platform-26/hub-rhel9, ansible-automation-platform-26/gateway-rhel9, ansible-automation-platform-26/controller-rhel9, ansible-automation-platform-25/ee-supported-rhel8, ansible-automation-platform-26/ee-supported-rhel9 Red Hat Enterprise Linux 6 python-lxml Red Hat Enterprise Linux 7 python-lxml
    +8 more products
    Red Hat Enterprise Linux 8 python-lxml, python3-lxml Red Hat Enterprise Linux 9 python-lxml, python3-lxml Red Hat Enterprise Linux 10 python-lxml Red Hat OpenShift AI (RHOAI) rhoai/odh-ta-lmes-job-rhel9, rhoai/odh-pipeline-runtime-pytorch-llmcompressor-cuda-py312-rhel9, rhoai/odh-workbench-jupyter-pytorch-llmcompressor-cuda-py312-rhel9 Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-9, openshift4/ose-olm-catalogd-rhel9 Red Hat Quay 3 quay/quay-rhel8, quay/quay-rhel9 Red Hat Satellite 6 python-lxml, python3-lxml Red Hat Update Infrastructure 4 for Cloud Providers python-lxml
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Hardened Images jq, mariadb11.8, python3-mypy, python-jsonschema, python-referencing, abattis-cantarell-fonts
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
6mo ago

Exploit prediction

0.32% chance of exploitation in the next 30 days, higher than 25% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • bugs.launchpad.net https://bugs.launchpad.net/lxml/+bug/2146291 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
pypi lxml
<6.1.0
6.1.0

Affected products

  • lxml lxml

Classification

Weakness
  • CWE-611 Improper Restriction of XML External Entity Reference

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.