No exploitation reportedFix available

CVE-2026-41066

Q: Is CVE-2026-41066 actively exploited?

Active exploitation of CVE-2026-41066 has not been confirmed. Its EPSS score was 0.3% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2026-41066?

CVE-2026-41066 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

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

No exploitation reported by the sources we read.

Published2026-04-24
Fixed in6.1.0
WeaknessCWE-611

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC

2026-04-2417:16CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-41066?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-41066?format=csv
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Versions per branch

NVD · OSV

Lxml

Branch	Affected	Fixed in	Source
6.1	< 6.1.0	6.1.0	NVD · OSV

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Vendor advisories

CVE-2026-41066 Red Hat Product Security29 known affected
lxml: python: lxml: Information disclosure via untrusted XML input leading to local file read
mta/mta-solution-server-rhel9 as a component of Migration Toolkit for Applications 8 · pen-drive/pen-drive-scanner-rhel9 as a component of Pen Drive Powered by Red Hat Lightspeed · rhaiis/vllm-neuron-rhel9 as a component of Red Hat AI Inference Server · +26 more

Full record on NVD

Fix

Update Lxml to 6.1.0
Workaround from the vendor Red Hat Product Security CVE-2026-41066 · 29 productsApplications using the lxml library to process untrusted XML input should explicitly configure the parser to prevent external entity resolution. This can be achieved by setting the `resolve_entities` option to `False` or `'internal'` when initializing the parser. For example, `etree.XML(xml_input, …
No fix available, says the vendor Red Hat Product Security CVE-2026-41066 · 29 productsFix deferred

Advisories and patches

github.comMitigation · Vendor Advisory

Detection

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: none listed

Sources

NVDCVE recordread 2026-10-23
CISA-ADPSSVC decisionnone2026-04-24
OpenCVESSVC decisionnone—
CNACVSS 3.17.5read 2026-10-23
CNAweakness (CWE)CWE-611read 2026-10-23
FIRST EPSSEPSS score0.3 %2026-10-23
OSVaffected packages—
Microsoft MSRCadvisory—

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Published: 2026-04-24
Last Modified: 2026-06-17
NVD status: Analyzed
MSRC Title: lxml: Default configuration of iterparse() and ETCompatXMLParser() allows XXE to local files

Frequently asked questions

What is CVE-2026-41066?

Is CVE-2026-41066 actively exploited?

Active exploitation of CVE-2026-41066 has not been confirmed. Its EPSS score was 0.3% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2026-41066?

CVE-2026-41066 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

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