Introduction
Privilege escalation in cloud messaging infrastructure can disrupt business workflows and compromise the integrity of notifications sent to millions of users. CVE-2025-59500 affects Azure Notification Service, a core Microsoft Azure service that handles cross-platform push notifications for enterprise and consumer applications. The affected component, Azure Notification Hubs, is widely used to deliver messages to iOS, Android, and Windows devices at scale.
Technical information
CVE-2025-59500 is an improper access control vulnerability (CWE-284) in Azure Notification Service. The service uses Shared Access Signature (SAS) policies to manage permissions for operations such as Listen, Send, and Manage. Each SAS policy is meant to restrict a user or application to specific actions within a notification hub. Client apps, for example, typically receive Listen-only permissions, while backend systems may be granted broader access.
The vulnerability lets an attacker with valid credentials and limited privileges (for example, Listen) perform actions that should be restricted to higher privilege levels (such as Send or Manage). The cause is insufficient enforcement of privilege boundaries in the service's access control logic. The flaw is remotely exploitable (CVSS v3.1: AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N) and does not require user interaction. The primary impact is on integrity, because an attacker can perform unauthorized operations. There is no direct impact on confidentiality or availability.
No public sources provide code snippets, exploit details, or detection methods for this vulnerability.
Affected systems and versions
The affected product is Azure Notification Service (Notification Hubs). Public sources give no specific version numbers or configuration details.
Vendor security history
Microsoft Azure has previously fixed improper access control and privilege escalation vulnerabilities in its cloud services, including Azure Automation and Azure Entra ID. The October 2025 Patch Tuesday included the largest number of fixes for the year, among them several privilege escalation flaws across Azure services. Microsoft typically responds with monthly security updates and has a mature process for vulnerability disclosure and remediation.
