CVE-2026-89058
HighCVSS 7.4Exploitation Probability (EPSS)
Low risk27th percentile - higher than 27% of all known CVEs
Summary
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.
Risk Assessment
A malicious website can read data from an authenticated user session, leading to information leakage and potential account takeover.
Recommendation
Update RESTEasy to a version containing the fix, and configure CorsFilter with an explicit allowlist of origins instead of "*" combined with credentials.
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-2026-17615High
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 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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS