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CVE-2026-61586NVD status: Deferred

copernik-xml-factory: Improper Restriction of XML External Entity Reference

CVE-2026-61586 is a high-severity improper restriction of XML external entity reference vulnerability in copernik-xml-factory from Copernik-eu, with a CVSS 4.0 base score of 8.2 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected copernik-xml-factory versions: < 0.1.2. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.36% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of copernik-xml-factory you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
Copernik-eucopernik-xml-factory< 0.1.2Not stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Attack requirements
PresentThe target must be in a specific state or configuration for the attack to work.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Confidentiality (vulnerable system)
HighSerious loss of confidentiality on the vulnerable system.
Integrity (vulnerable system)
NoneNo loss of integrity on the vulnerable system.
Availability (vulnerable system)
NoneNo loss of availability on the vulnerable system.
Confidentiality (other systems)
NoneNo loss of confidentiality on systems beyond the vulnerable one.
Integrity (other systems)
NoneNo loss of integrity on systems beyond the vulnerable one.
Availability (other systems)
NoneNo loss of availability on systems beyond the vulnerable one.

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA (github.com).

Official 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Restriction of XML External Entity Reference

The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.

How developers prevent this class of flaw

  • Many XML parsers and validators can be configured to disable external entity expansion.

More Improper Restriction of XML External Entity Reference vulnerabilities (CWE-611)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Improper Restriction of XML External Entity Reference vulnerabilities

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