CVE-2026-41066

Published: April 29, 2026Last modified: May 10, 2026

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.

Severity score breakdown

ParameterValue
Base score7.5
Attack VectorNETWORK
Attack complexityLOW
Privileges requiredNONE
User interactionNONE
ScopeUNCHANGED
ConfidentialityHIGH
Integrity impactNONE
Availability impactNONE
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Notes

In lxml 5.0.0: https://bugs.launchpad.net/lxml/+bug/1742885 https://github.com/lxml/lxml/pull/391 the default value of `resolve_entities` was not updated for `etree.iterparse()` and `ETCompatXMLParser()` entry points. This CVE is exactly about these two entry points. Since 23 LTS provides an older version (4.9.3) we decided not to change the default. It's recommended to avoid the CVE by following upstream recommendations: https://lxml.de/FAQ.html#how-do-i-use-lxml-safely-as-a-web-service-endpoint

Status

ProductReleasePackageStatus
Alpaquita Linux23 LTSpy3-lxmlWill not fix (4.9.1-r1)
25 LTSpy3-lxmlFixed (5.3.1-r1)
Streampy3-lxmlFixed (6.1.0-r0)

References

ON THIS PAGE