CVE-2026-17615: Resteasy-core: resteasy sourceprovider remote unauthenticated file read
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
Event History
Frequently Asked Questions
Which endpoints should be prioritized for review?
Prioritize endpoints that accept application/xml request bodies and return Source or StreamSource. Those endpoints can trigger external entity resolution during SourceProvider.writeTo().
Does exploitation require authentication or user interaction?
No. The reported vector is network-accessible, requires no privileges, and requires no user interaction.
What can an attacker obtain if exploitation succeeds?
An attacker can cause the server to resolve an external entity and include sensitive file contents in the HTTP response.