CVE-2026-89058
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.
Weakness
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.
References
- https://access.redhat.com/security/cve/CVE-2026-89058
- https://bugzilla.redhat.com/show_bug.cgi?id=2519775
- https://github.com/resteasy/resteasy/commit/efeb2b7
- https://github.com/resteasy/resteasy/security/advisories/GHSA-972r-f3fv-whm3
- https://github.com/resteasy/resteasy/security/advisories/GHSA-972r-f3fv-whm3
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