Microsoft has published a new security advisory for a confirmed information disclosure vulnerability in Power Automate Desktop, tracked as CVE-2026-40374. The announcement came via the company’s Security Update Guide, the central hub for Microsoft’s vulnerability disclosures and patch documentation. Power Automate Desktop, the Windows-based robotic process automation (RPA) tool, enables users to build automated workflows that interact with local and web-based applications, making it a critical piece of many enterprise environments. An information disclosure flaw in such a tool could expose sensitive data handled during automation, including credentials, session tokens, or proprietary business information.

The publication of CVE-2026-40374 confirms that Microsoft is aware of an exploitable weakness in the desktop client. While the advisory itself is sparse on technical details, typical information disclosure vulnerabilities in automation platforms arise from improper handling of debug logs, temporary files, or memory dumps that inadvertently store plaintext credentials or other secrets. Attackers with local or remote access—depending on the attack vector—could potentially read this data, escalating their foothold in a compromised system.

What is Power Automate Desktop?

Power Automate Desktop (PAD) extends the Power Automate cloud platform to the Windows desktop, empowering non-developers to record and execute automated processes. Activities include file manipulation, UI interaction, database queries, and integration with legacy applications. Enterprises rely heavily on PAD to streamline repetitive tasks, but this reliance also means that a vulnerability could expose the credentials used for those automated logins—usernames, passwords, and API keys stored within the flow definitions.

Because PAD can run unattended on servers or virtual machines, an information disclosure bug might give an attacker who gains low-privilege access a pathway to retrieve credentials that the automated process uses to access sensitive systems. Even with limited user rights, reading in-memory data or unprotected configuration files could yield domain-level credentials, making this a potentially high-impact vulnerability.

Understanding Information Disclosure Vulnerabilities

An information disclosure vulnerability occurs when a system inadvertently reveals data that should be protected. In the context of desktop automation software, common vectors include:

  • Improper logging: The application writes sensitive data to plaintext log files that are readable by other users.
  • Insecure temporary files: Automations may cache credentials or session data in temporary directories with weak access controls.
  • Memory scraping: A local attacker with process inspection tools can dump the application’s memory and search for plaintext credentials.
  • Leaked debugging information: Error messages or debug modes may output internal paths, tokens, or configuration values.

CVSS scoring for such flaws often falls in the Important severity range (6.0–7.9) because exploitation typically requires local access or authenticated network access to the machine running the vulnerable software. However, if the vulnerability can be triggered remotely without user interaction, the severity jumps to Critical. Microsoft has not publicly provided the CVSS score for CVE-2026-40374, but the fact that it is listed in the Security Update Guide suggests a fix is available and that organizations should prioritize patching.

Details of CVE-2026-40374

The CVE record for CVE-2026-40374, as published in the Microsoft Security Update Guide, confirms:

  • Product: Microsoft Power Automate Desktop
  • Vulnerability type: Information Disclosure
  • Status: Confirmed, patch available

No additional technical details—such as the affected component, attack vector, or required privileges—have been released. That is standard practice for Microsoft; the bulletin serves as an authoritative notice, while the detailed mitigation is delivered via the update itself. Security researchers and enterprise administrators often rely on the CVSS vector string and the accompanying knowledge base article (if published) to gauge the risk, but at the time of writing, the advisory provides only the high-level classification.

The CVE identifier uses the 2026 numbering block, indicating that this vulnerability was assigned a tracking ID in 2026. However, the publication date in the Security Update Guide might be from a later period—Microsoft CVEs are often published on Patch Tuesday, so admins should check their patch management timelines.

How This Vulnerability Could Be Exploited

Although the specific mechanics of CVE-2026-40374 remain under wraps, we can sketch a plausible attack scenario based on common RPA weaknesses:

  1. A low-privilege user or a piece of malware gains code execution on a system running Power Automate Desktop.
  2. The process hosting the automation engine stores credentials—perhaps a service account password used to log into a web application—in a predictable memory location or on disk.
  3. The attacker reads that data using file I/O or memory inspection, then exfiltrates the credentials.
  4. With the stolen credentials, the attacker moves laterally within the network, potentially accessing SQL databases, SharePoint sites, or admin panels previously automated by Power Automate Desktop.

In real-world assessments, penetration testers have demonstrated that PAD can leave secrets behind in the %TEMP% folder or within the C:\ProgramData\Microsoft\Power Automate Desktop directory if cleanup routines fail. Microsoft’s fix likely corrects such a path or introduces encryption for stored secrets.

Microsoft’s Response and Patching

Microsoft’s Security Update Guide entry for CVE-2026-40374 implies that the vulnerability has been resolved through a security update. The advisory itself does not list a KB article number, but it does direct users to the Microsoft Update Catalog or Windows Update. Typically, Power Automate Desktop updates are delivered via the Microsoft Store or the built-in auto-update mechanism of the desktop client.

To obtain the patch, users should:

  • Open Power Automate Desktop and navigate to Settings > About
  • Click Check for updates to install the latest version
  • Alternatively, download the latest installer from the official Power Automate Desktop download page

Organizations using WSUS or Configuration Manager can deploy the update through those channels if they manage desktop applications. For standalone machines, the auto-update should prompt for a restart and apply the fix without manual intervention.

It’s worth noting that the vulnerability was disclosed publicly before any known exploits were observed in the wild, a practice that falls under coordinated vulnerability disclosure. However, now that the CVE is public, threat actors may attempt to reverse-engineer the patch and develop proof-of-concept exploits. Therefore, timely patching is critical.

How to Protect Your System

Beyond applying the patch, there are several best practices that can mitigate the risk of information disclosure in automation environments:

  • Run automations under dedicated service accounts with the minimum required privileges. Avoid using domain admin accounts for desktop flows.
  • Enable Windows Defender Credential Guard and other isolation technologies to protect secrets in memory.
  • Audit Power Automate Desktop logs regularly to ensure no sensitive data is being inadvertently written to plaintext files.
  • Encrypt the disk where Power Automate Desktop stores its data (typically the system drive) using BitLocker.
  • Restrict access to machines running unattended RPA bots; these should be treated as privileged endpoints.
  • Monitor for suspicious process behavior, such as unexpected reads of Power Automate Desktop process memory or modifications to its configuration files.

What This Means for Windows Enthusiasts and IT Admins

The publication of CVE-2026-40374 is a reminder that automation tools, while powerful, expand the attack surface. Each automation that logs into a service adds a credential that must be protected. Microsoft’s quick fix for this information disclosure vulnerability shows ongoing investment in securing its RPA platform, but administrators must do their part by applying updates and hardening their installations.

For home users or small businesses that use Power Automate Desktop to automate personal tasks, the risk is lower, but updating is still recommended. The convenience of automated workflows should never come at the expense of security.

Looking forward, we can expect Microsoft to continue tightening the security of Power Automate Desktop as the product matures. With RPA becoming a staple in enterprise IT, vulnerabilities like CVE-2026-40374 will be closely watched by both defenders and attackers. The full technical details may emerge in the coming weeks as researchers analyze the patch, but for now, applying the update is the single most effective action you can take.

To stay informed, bookmark the Microsoft Security Update Guide and subscribe to Patch Tuesday alerts. As always, we will follow up on CVE-2026-40374 if additional details or proof-of-concept code surface.