Critical Microsoft Power Apps Flaw Discovered

Microsoft has disclosed a critical vulnerability, tracked as CVE-2026-59118, affecting Microsoft Power Apps. The flaw stems from improper authorization, which enables an unauthorized attacker to perform privilege escalation over a network.

With a CVSS 3.1 score of 9.3, this vulnerability is classified as critical. The attack vector is identified as network-based, requiring low attack complexity, though it does involve user interaction. Successful exploitation grants an attacker the ability to elevate privileges, impacting the confidentiality and integrity of the affected systems.

What's at Risk

The vulnerability impacts users of Microsoft Power Apps. Organizations that rely on this platform for business process automation, data management, or internal application hosting are at risk if their environments remain unpatched. Systems exposed to the public internet are generally at a higher risk, as they provide a broader surface for unauthorized network-based access attempts.

Because the flaw allows for privilege escalation, any account or service principal integrated with Power Apps could potentially be compromised. This makes the vulnerability particularly dangerous for enterprises that utilize Power Apps to handle sensitive data or manage cross-departmental workflows.

How the Flaw Works

Improper authorization vulnerabilities occur when an application fails to adequately verify that a user or process has the permissions required to perform a specific action or access a resource. In general, these flaws allow an attacker to bypass security controls by manipulating requests to the application. When an application trusts user-supplied input or fails to enforce strict access control checks at the server side, an attacker can often escalate their privileges to match those of a more powerful user, such as an administrator.

In the context of network-based exploitation, this class of vulnerability typically involves the attacker sending specially crafted packets or requests to the service. If the authorization logic is flawed, the system may grant the attacker access to administrative functions, data that should be restricted, or the ability to modify system configurations that are otherwise off-limits to standard users.

How to Protect Your Systems

• Review the official Microsoft Security Response Center update guide for CVE-2026-59118 to identify and apply the necessary security patches.
• Ensure all Power Apps environments are updated to the latest available software versions provided by the vendor.
• Implement the principle of least privilege by auditing user permissions and restricting administrative access to only those who strictly require it.
• Monitor network logs for unusual traffic patterns or unauthorized attempts to access administrative endpoints within your Power Apps environment.
• Enforce multi-factor authentication (MFA) across all organizational accounts to add a layer of defense against unauthorized access attempts.

Given the critical severity of this flaw and its potential to facilitate privilege escalation, organizations should prioritize remediation. Promptly applying vendor patches is the most effective way to eliminate the underlying vulnerability and prevent attackers from leveraging this authorization weakness to gain unauthorized control over business-critical systems.