# CVE-2026-41066: lxml: Default configuration of iterparse() and ETCompatXMLParser() allows XXE to local files

CVE-2026-41066 is fixed in 8 products on 1 platform, first by ALAS2023-2026-1678, released May 11, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-41066
- Priority: High
- CVSS: 7.5 (Important)
- EPSS: 0.0032
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 24, 2026
- Weakness: Improper Restriction of XML External Entity Reference
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-41066

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | lxml Debian 12.15 (bookworm) | 4.9.2-1+deb12u1 | [DEBIAN-CVE-2026-41066](https://patchblox.com/security/data/fix/linux/debian-cve-2026-41066.md) | May 15, 2026 |
| Linux | lxml Debian 14 | 6.1.0-1 | [DEBIAN-CVE-2026-41066](https://patchblox.com/security/data/fix/linux/debian-cve-2026-41066.md) | May 15, 2026 |
| Linux | python-lxml Ubuntu 18.04.6 LTS (bionic) | 4.2.1-1ubuntu0.6+esm1 | [python-lxml 4.2.1-1ubuntu0.6+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python-lxml-4.2.1-1ubuntu0.6-esm1.md) | Aug 20, 2026 |
| Linux | python-lxml Ubuntu 20.04 LTS (focal) | 4.5.0-1ubuntu0.5+esm1 | [python-lxml 4.5.0-1ubuntu0.5+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-python-lxml-4.5.0-1ubuntu0.5-esm1.md) | Aug 20, 2026 |
| Linux | python-lxml sles 15.7 | 4.9.3-150400.8.11.1 | [SUSE-SU-2026:2729-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2729-1.md) | Jul 2, 2026 |
| Linux | python-lxml-debugsource amzn 2023 | 4.7.1-3.amzn2023.0.3 | [ALAS2023-2026-1678](https://patchblox.com/security/data/fix/linux/alas2023-2026-1678.md) | May 11, 2026 |
| Linux | python3-lxml Ubuntu 18.04.6 LTS (bionic) | 4.2.1-1ubuntu0.6+esm1 | [python3-lxml 4.2.1-1ubuntu0.6+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-python3-lxml-4.2.1-1ubuntu0.6-esm1.md) | Aug 20, 2026 |
| Linux | python3-lxml Ubuntu 20.04 LTS (focal) | 4.5.0-1ubuntu0.5+esm1 | [python3-lxml 4.5.0-1ubuntu0.5+esm1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-python3-lxml-4.5.0-1ubuntu0.5-esm1.md) | Aug 20, 2026 |
| Linux | python3-lxml Ubuntu 22.04.1 LTS (jammy) | 4.8.0-1ubuntu0.1 | [python3-lxml 4.8.0-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-python3-lxml-4.8.0-1ubuntu0.1.md) | Aug 20, 2026 |
| Linux | python3-lxml Ubuntu 24.04.5 LTS (noble) | 5.2.1-1ubuntu0.2 | [python3-lxml 5.2.1-1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-noble-python3-lxml-5.2.1-1ubuntu0.2.md) | Aug 20, 2026 |
| Linux | python3-lxml Ubuntu 26.04.1 LTS (resolute) | 6.0.2-1ubuntu0.1 | [python3-lxml 6.0.2-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-python3-lxml-6.0.2-1ubuntu0.1.md) | Aug 20, 2026 |
| Linux | python3-lxml amzn 2023 | 4.7.1-3.amzn2023.0.3 | [ALAS2023-2026-1678](https://patchblox.com/security/data/fix/linux/alas2023-2026-1678.md) | May 11, 2026 |
| Linux | python3-lxml sles 15.7 | 4.9.1-150500.3.7.1 | [SUSE-SU-2026:2754-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2754-1.md) | Jul 3, 2026 |
| Linux | python3-lxml-debuginfo amzn 2023 | 4.7.1-3.amzn2023.0.3 | [ALAS2023-2026-1678](https://patchblox.com/security/data/fix/linux/alas2023-2026-1678.md) | May 11, 2026 |
| Linux | python3.13-lxml amzn 2023 | 5.3.2-3.amzn2023.0.2 | [ALAS2023-2026-1679](https://patchblox.com/security/data/fix/linux/alas2023-2026-1679.md) | May 11, 2026 |
| Linux | python3.13-lxml-debuginfo amzn 2023 | 5.3.2-3.amzn2023.0.2 | [ALAS2023-2026-1679](https://patchblox.com/security/data/fix/linux/alas2023-2026-1679.md) | May 11, 2026 |
| Linux | python3.13-lxml-debugsource amzn 2023 | 5.3.2-3.amzn2023.0.2 | [ALAS2023-2026-1679](https://patchblox.com/security/data/fix/linux/alas2023-2026-1679.md) | May 11, 2026 |

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Data as of 2026-11-09T07:25:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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