CVE-2026-57111
Permissive Cross-Origin Resource Sharing (CORS) in the REST API (helix-rest, org.apache.helix.rest.server.filters.CORSFilter) in Apache Helix through 2.0.0 on all platforms allows a remote attacker controlling a web page visited by an authorized user to read responses from and issue cross-origin requests to administrative REST endpoints via a cross-origin request from an arbitrary origin, since the filter unconditionally returns Access-Control-Allow-Origin: * together with Access-Control-Allow-Credentials: true and reflects arbitrary Access-Control-Request-Method / Access-Control-Request-Headers values in preflight responses. Users are recommended to upgrade to version 2.0.1, which fixes this issue.
No public exploitation has been reported so far. No distribution fix is listed yet; apply vendor mitigations and monitor.
Recommended action: Track your distribution's security tracker and apply the fix as soon as it ships.
Severity metrics
CVSS 3.1 : 7.5 HIGH
Vector: AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Affected & fixed versions by distribution
Versions are the native distribution strings (backport-aware): RHEL/Debian/SUSE backport fixes, so compare with the distro version comparator (dpkg / rpm / vercmp), not the upstream version.
No affected package in the tracked watchlist yet (Debian, Ubuntu, Arch, SUSE, Red Hat...). Triage may still be pending.