Use of Multiple Resources with Duplicate Identifier (CWE-694) in APM Server can lead to information disclosure via a specially crafted agent configuration request. An authenticated APM agent could receive the central agent configuration that belongs to a different service until the cached configuration expires. A service could also run with central configuration settings, such as sampling settings, that were meant for a different service.
https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-116071
https://discuss.elastic.co/t/apm-server-8-19-24-9-4-9-9-5-6-security-update-esa-2026-200/391355