CVE-2026-81936: Default OpenBMC Root Credential Reintroduced After Reset to Defaults in ThinkSystem v4 XCC3

An internal security review identified a development regression from ThinkSystem v4 XClarity Controller 3 (XCC3) versions (2.51) IHX432Y to (2.56) IHX436K which re-introduces the default OpenBMC root password upon performing an XCC Reset to Default operation.  An attacker can gain access to enabled administrative interfaces of XCC using the default OpenBMC credential re-introduced after Reset to Default. Additionally, this provides access to the underlying XCC Operating System which is not normally accessible. Only these versions are affected and are no longer available for download. Process enhancements have also been made to prevent and identify potential future regression.