Sentry is an error tracking and performance monitoring platform. Starting in version 23.6.0 and prior to version 23.6.2, the Sentry API incorrectly returns the `access-control-allow-credentials: true` HTTP header if the `Origin` request header ends with the `system.base-hostname` option of Sentry installation. This only affects installations that have `system.base-hostname` option explicitly set, as it is empty by default. Impact is limited since recent versions of major browsers have cross-site cookie blocking enabled by default. However, this flaw could allow other multi-step attacks. The patch has been released in Sentry 23.6.2.