CVE-2026-89140 Temporal Server internal completion callbacks are not bound to their namespace, allowing cross-namespace changes to Scheduler V2 schedule state

Temporal Server does not bind internal completion callbacks to the namespace that attached them, which allows an authenticated caller with write permission in one namespace to alter Scheduler V2 schedule state in another namespace. The callback address temporal://internal is reserved for callback...

CVE-2026-89140

The Temporal Server contains a vulnerability where internal completion callbacks are not bound to their specific namespaces. This allows an authenticated caller with write permissions in one namespace to manipulate the Scheduler V2 schedule state in a different namespace. The flaw exists because ...