CVE-2026-61586

Copernik XML Factory provides secure-by-default JAXP factory creation for Java. Prior to 0.1.2, Copernik XML Factory does not block XInclude resource resolution on the stock JDK provider after an application enables XInclude on a factory returned by XmlFactories.newDocumentBuilderFactory() or XmlFactories.newSAXParserFactory(), or on an XMLReader passed through XmlFactories.harden(). An application parsing untrusted XML can resolve attacker-controlled xi:include references to disclose local files or, through http references, reach internal network endpoints by server-side request forgery. Exploitation requires use of one of those factory/hardening APIs, the stock JDK provider with Apache Xerces absent from the classpath, explicit setXIncludeAware(true) or the equivalent reader feature, and XML from an untrusted source. The Xerces provider selected when Xerces is present and the Android provider are unaffected. This issue is fixed in version 0.1.2.

Copernik XML Factory provides secure-by-default JAXP factory creation for Java. Prior to 0.1.2, Copernik XML Factory does not block XInclude resource resolution on the stock JDK provider after an application enables XInclude on a factory returned by XmlFactories.newDocumentBuilderFactory() or XmlFactories.newSAXParserFactory(), or on an XMLReader passed through XmlFactories.harden(). An application parsing untrusted XML can resolve attacker-controlled xi:include references to disclose local files or, through http references, reach internal network endpoints by server-side request forgery. Exploitation requires use of one of those factory/hardening APIs, the stock JDK provider with Apache Xerces absent from the classpath, explicit setXIncludeAware(true) or the equivalent reader feature, and XML from an untrusted source. The Xerces provider selected when Xerces is present and the Android provider are unaffected. This issue is fixed in version 0.1.2.

Copernik XML Factory through 0.1.1, when running on its stock JDK provider, does not block XInclude resource resolution after an application enables XInclude on a factory returned by XmlFactories.newDocumentBuilderFactory() or XmlFactories.newSAXParserFactory(), or on an XMLReader passed through XmlFactories.harden(). The library's documented guarantee that XInclude resolution stays disabled therefore does not hold on that provider.

An application that parses untrusted XML in this configuration can be made to resolve xi:include references, allowing an attacker to read local files (information disclosure) or, through http hrefs, reach internal network endpoints (SSRF).

All of the following conditions must hold for an application to be affected:

• it obtains a factory from XmlFactories.newDocumentBuilderFactory() or XmlFactories.newSAXParserFactory(), or hardens an externally obtained XMLReader with XmlFactories.harden();
• the stock JDK provider is in effect, that is, Apache Xerces is not on the classpath;
• XInclude is enabled, by calling setXIncludeAware(true) or the equivalent reader feature;
• it parses XML from an untrusted source.

The Xerces provider (selected when Xerces is on the classpath) and the Android provider are not affected.

Applications are advised to upgrade to 0.1.2, which fixes the defect. As a workaround add Apache Xerces (xercesImpl) to the classpath so the library selects its unaffected Xerces provider.

Acknowledgements

The maintainer thank the following people for finding, reporting, and helping to remediate this issue:

• Finders: Ta Duc Thien and Duc Anh Nguyen (Danzation)
• Remediation developer: Ta Duc Thien
• Tooling: Claude Code (Anthropic), Claude Opus 4.8

Copernik XML Factory provides secure-by-default JAXP factory creation for Java. Prior to 0.1.2, Copernik XML Factory does not block XInclude resource resolution on the stock JDK provider after an application enables XInclude on a factory returned by XmlFactories.newDocumentBuilderFactory() or XmlFactories.newSAXParserFactory(), or on an XMLReader passed through XmlFactories.harden(). An application parsing untrusted XML can resolve attacker-controlled xi:include references to disclose local files or, through http references, reach internal network endpoints by server-side request forgery. Exploitation requires use of one of those factory/hardening APIs, the stock JDK provider with Apache Xerces absent from the classpath, explicit setXIncludeAware(true) or the equivalent reader feature, and XML from an untrusted source. The Xerces provider selected when Xerces is present and the Android provider are unaffected. This issue is fixed in version 0.1.2.

Copernik XML Factory provides secure-by-default JAXP factory creation for Java. Prior to 0.1.2, Copernik XML Factory does not block XInclude resource resolution on the stock JDK provider after an application enables XInclude on a factory returned by XmlFactories.newDocumentBuilderFactory() or XmlFactories.newSAXParserFactory(), or on an XMLReader passed through XmlFactories.harden(). An application parsing untrusted XML can resolve attacker-controlled xi:include references to disclose local files or, through http references, reach internal network endpoints by server-side request forgery. Exploitation requires use of one of those factory/hardening APIs, the stock JDK provider with Apache Xerces absent from the classpath, explicit setXIncludeAware(true) or the equivalent reader feature, and XML from an untrusted source. The Xerces provider selected when Xerces is present and the Android provider are unaffected. This issue is fixed in version 0.1.2.

Copernik XML Factory through 0.1.1, when running on its stock JDK provider, does not block XInclude resource resolution after an application enables XInclude on a factory returned by XmlFactories.newDocumentBuilderFactory() or XmlFactories.newSAXParserFactory(), or on an XMLReader passed through XmlFactories.harden(). The library's documented guarantee that XInclude resolution stays disabled therefore does not hold on that provider.

An application that parses untrusted XML in this configuration can be made to resolve xi:include references, allowing an attacker to read local files (information disclosure) or, through http hrefs, reach internal network endpoints (SSRF).

All of the following conditions must hold for an application to be affected:

• it obtains a factory from XmlFactories.newDocumentBuilderFactory() or XmlFactories.newSAXParserFactory(), or hardens an externally obtained XMLReader with XmlFactories.harden();
• the stock JDK provider is in effect, that is, Apache Xerces is not on the classpath;
• XInclude is enabled, by calling setXIncludeAware(true) or the equivalent reader feature;
• it parses XML from an untrusted source.

The Xerces provider (selected when Xerces is on the classpath) and the Android provider are not affected.

Applications are advised to upgrade to 0.1.2, which fixes the defect. As a workaround add Apache Xerces (xercesImpl) to the classpath so the library selects its unaffected Xerces provider.

Acknowledgements

The maintainer thank the following people for finding, reporting, and helping to remediate this issue:

• Finders: Ta Duc Thien and Duc Anh Nguyen (Danzation)
• Remediation developer: Ta Duc Thien
• Tooling: Claude Code (Anthropic), Claude Opus 4.8