XML Notepad is a Windows program that provides a simple intuitive User Interface for browsing and editing XML documents. Prior to version 2.9.0.21, XML Notepad does not disable DTD processing by default which means external entities are resolved automatically. There is a well known attack related to malicious DTD files where an attacker to craft a malicious XML file that loads a DTD that causes XML Notepad to make outbound HTTP/SMB requests, potentially leaking local file contents or capturing the victim's NTLM credentials. This issue has been patched in version 2.9.0.21.
Metrics
Affected Vendors & Products
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History
Thu, 02 Apr 2026 20:30:00 +0000
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Microsoft
Microsoft xmlnotepad |
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Microsoft
Microsoft xmlnotepad |
Wed, 01 Apr 2026 23:45:00 +0000
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ssvc
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Wed, 01 Apr 2026 02:15:00 +0000
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| Description | XML Notepad is a Windows program that provides a simple intuitive User Interface for browsing and editing XML documents. Prior to version 2.9.0.21, XML Notepad does not disable DTD processing by default which means external entities are resolved automatically. There is a well known attack related to malicious DTD files where an attacker to craft a malicious XML file that loads a DTD that causes XML Notepad to make outbound HTTP/SMB requests, potentially leaking local file contents or capturing the victim's NTLM credentials. This issue has been patched in version 2.9.0.21. | |
| Title | XML Notepad: XML External Entity (XXE) Injection via Unsafe XmlTextReader in XML Diff and Schema Loading | |
| Weaknesses | CWE-611 | |
| References |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: GitHub_M
Published: 2026-03-31T21:05:50.647Z
Updated: 2026-04-01T15:53:18.538Z
Reserved: 2026-03-27T13:45:29.620Z
Link: CVE-2026-34401
Updated: 2026-04-01T15:45:51.351Z
Status : Awaiting Analysis
Published: 2026-03-31T22:16:18.490
Modified: 2026-04-01T17:28:40.303
Link: CVE-2026-34401
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