GCVE-110-CLOUD-2025-0028

A critical vulnerability discovered in Microsoft's Entra ID (formerly Azure AD) allowed for cross-tenant access and potential global admin privilege escalation. The flaw was found in the legacy Azure AD Graph API, which improperly validated the originating tenant for undocumented "Actor tokens." An attacker could use a token from their own tenant to authenticate as any user, including Global Admins, in any other tenant. This vulnerability bypassed security policies like Conditional Access. The issue was reported to Microsoft, who deployed a global fix within days.