CVE-2026-34762: Ella Core Has Audit Log Falsification via Path/Body IMSI Mismatch in UpdateSubscriber

The PUT /api/v1/subscriber/{imsi} API accepts an IMSI identifier from both the URL path and the JSON request body but never verifies they match. This allows an authenticated NetworkManager to modify any subscriber’s policy while the audit trail records a fabricated or unrelated subscriber IMSI.