CVE-2026-34401 | BDVDB-2026-323975 Detail
MicrosoftXmlNotepad
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.
Impact#
Per CVSS v3.1: confidentiality impact high, integrity impact none, availability impact none. Attack vector: network.
Weaknesses#
- CWE-611 Improper Restriction of XML External Entity Reference
References#
- https://github.com/microsoft/XmlNotepad/security/advisories/GHSA-5j32-486h-42ch
- https://github.com/microsoft/XmlNotepad/commit/3665603d61ba10b7827a3724e854748cb780140c
- https://github.com/microsoft/XmlNotepad/commit/c03ab2311ac6960452eb1ab49098768f851dcc53
- https://github.com/microsoft/XmlNotepad/releases/tag/2.9.0.21
Exploit#
No public exploit known
History#
- Version 1Record published in the CVE List.
- Version 2Most recent update recorded in the CVE List.