CVE-2026-34401
MEDIUM
6,5
Source: [email protected]
Attack Vector: network
Attack Complexity: low
Privileges Required: none
User Interaction: required
Scope: unchanged
Confidentiality: high
Integrity: none
Availability: none
Description
AI Translation Available
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.
611
Improper Restriction of XML External Entity Reference
DraftCommon Consequences
Security Scopes Affected:
Confidentiality
Integrity
Availability
Potential Impacts:
Read Application Data
Read Files Or Directories
Bypass Protection Mechanism
Dos: Resource Consumption (Cpu)
Dos: Resource Consumption (Memory)
Applicable Platforms
Languages:
Not Language-Specific, XML
Technologies:
Not Technology-Specific, Web Based
https://github.com/microsoft/XmlNotepad/commit/3665603d61ba10b7827a3724e854748c…
https://github.com/microsoft/XmlNotepad/commit/c03ab2311ac6960452eb1ab49098768f…
https://github.com/microsoft/XmlNotepad/releases/tag/2.9.0.21
https://github.com/microsoft/XmlNotepad/security/advisories/GHSA-5j32-486h-42ch