CVE-2026-17615

Summary

A flaw was found in RESTEasy's SourceProvider. This vulnerability allows an unauthenticated attacker to perform an unauthenticated remote file read. By sending a specially crafted XML body with a DOCTYPE declaration referencing external entities to an endpoint that accepts application/xml and returns Source or StreamSource, the server can be tricked into resolving the entity and including sensitive file contents in the HTTP response. This is due to the SourceProvider.writeTo() method creating a SAXParser without disabling external entity resolution, leading to an XML External Entity (XXE) vulnerability.

Affected Software

VendorProductVersion RangeStatus

Weaknesses

  • CWE-611: Improper Restriction of XML External Entity Reference

Workarounds

To mitigate this issue, avoid exposing RESTEasy endpoints that return Source or StreamSource types. Alternatively, implement a custom MessageBodyWriter for Source types that explicitly applies XML security features to the SAXParserFactory before parsing. Changes to application configuration or code typically require an application redeployment or restart to take effect.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

References