CVE-2026-41066Network attack vector

Local file disclosure via unsafe entity resolution

Published Apr 24, 2026 · Updated Apr 24, 2026

XXE in lxml before 6.1.0 allows remote attackers to read local files through untrusted XML passed to affected parser APIs. iterparse() and ETCompatXMLParser() retain resolve_entities=True as their default and therefore dereference external file entities during parsing. Exploitation requires an application to pass attacker-controlled XML to either API without overriding that default; disclosure is limited to files readable by the application process.

CVSS severity7.5
High
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

XXE in lxml before 6.1.0 allows remote attackers to read local files through untrusted XML passed to affected parser APIs. iterparse() and ETCompatXMLParser() retain resolve_entities=True as their default and therefore dereference external file entities during parsing. Exploitation requires an application to pass attacker-controlled XML to either API without overriding that default; disclosure is limited to files readable by the application process.

The record

CVE
CVE-2026-41066
Published
Apr 24, 2026
Updated
Apr 24, 2026
Vendor
lxml
Product
lxml
Classifications
CWE-611, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 24, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 24, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 6.1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

lxml · lxmlversion=< 6.1.0

Published CVSS scores

7.5Amazon LinuxCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
7.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-611Improper Restriction of XML External Entity Reference
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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