CVE-2026-120971
MediumCVSS 5.3Exploitation Probability (EPSS)
Low risk28th percentile - higher than 28% of all known CVEs
Summary
A flaw was found in RESTEasy's default exception mapper. When an unhandled exception other than a WebApplicationException is not handled by an application exception mapper, RESTEasy returns the exception's localized message in the HTTP 500 response body. A remote unauthenticated attacker who can trigger such an exception may obtain information contained in that message.
Risk Assessment
Leaking exception details may reveal internal application structure to an attacker and facilitate further attacks. The risk affects any RESTEasy-based application that does not intercept all exceptions.
Recommendation
Update RESTEasy to a patched version or implement a custom exception mapper that does not expose localized messages in HTTP 500 responses.
Other vulnerabilities in RESTEasy
See all- CVE-2016-6346High
RESTEasy enables GZIPInterceptor, allowing remote attackers to cause a denial of service via unspecified vectors.
- CVE-2014-3490High
RESTEasy versions 2.3.1 before 2.3.8.SP2 and 3.x before 3.0.9, used in Red Hat JBoss EAP 6.3.0, does not disable external entities when the resteasy.document.expand.entity.references parameter is set to false. This allows remote attackers to read arbitrary files and have other unspecified impacts related to an XML External Entity (XXE) issue.
- CVE-2026-89059High
A flaw was found in RESTEasy's IIOImageProvider, which decodes attacker-supplied image request bodies without enforcing any limit on the declared image dimensions or pixel count. A remote, unauthenticated attacker can send a small crafted image declaring enormous dimensions to trigger a very large memory allocation, exhausting the JVM heap and resulting in a denial of service.
- CVE-2026-89058High
A flaw was found in RESTEasy's CorsFilter, which, when configured to allow all origins ("*"), reflects the request's Origin header back in the Access-Control-Allow-Origin response together with Access-Control-Allow-Credentials: true. This permissive cross-origin policy allows a malicious website to make credentialed cross-origin requests and read authenticated responses from a victim's session, resulting in a loss of confidentiality.
- CVE-2026-17615High
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.
Original NVD description (English source)
A flaw was found in RESTEasy's default exception mapper. When an unhandled exception other than a WebApplicationException is not handled by an application exception mapper, RESTEasy returns the exception's localized message in the HTTP 500 response body. A remote unauthenticated attacker who can trigger such an exception may obtain information contained in that message. The behavior was reproduced with RESTEasy 7.0.2.Final.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS