What is CVE-2026-41066?

CVE-2026-41066 is a high-severity vulnerability in Lxml, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 7.5/10. Published 2026-04-24.

How severe is CVE-2026-41066?

High severity. CVSS v3 base score is 7.5 out of 10.

XXE in Lxml

CVE-2026-41066

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 res…

Vulnerability class: XXE (XML External Entity)

EPSS: 0.000 (14.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

Affected products

Lxml — versions < 6.1.0

Weakness classification (CWE)

CWE-611 — Improper Restriction of XML External Entity Reference (XXE)

References

https://github.com/lxml/lxml/security/advisories/GHSA-vfmq-68hx-4jfw (x_refsource_CONFIRM)
https://bugs.launchpad.net/lxml/+bug/2146291 (x_refsource_MISC)

Frequently asked questions

What is CVE-2026-41066?: CVE-2026-41066 is a high-severity vulnerability in Lxml, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 7.5/10. Published 2026-04-24.
How severe is CVE-2026-41066?: High severity. CVSS v3 base score is 7.5 out of 10.