Outlook Bug Causes Global Disruptions: Microsoft Investigates Login Failures and High Memory Usage

Introduction

Microsoft is currently investigating a significant issue affecting its Outlook desktop app, with users experiencing a range of problems, including crashes, high memory consumption, and login failures. Initially believed to impact only European users, the issue has now been reported by users globally, signaling a more widespread problem. In addition to the desktop app, some users have experienced similar issues while using Outlook on the web (OWA), making this a pressing matter for Microsoft to address.

Outlook Bug: Global Impact Beyond Europe

Microsoft initially acknowledged the problem, stating that the primary issues—crashes, non-delivery of emails, and excessive memory consumption—seemed to be affecting European customers. However, as the situation unfolded, users from other regions, including the United States, reported similar problems, suggesting the issue has a broader scope.

While the investigation was initially focused on European networks, specifically in the Netherlands, it quickly became apparent that this bug had the potential to impact other Microsoft 365 services as well. Some affected customers received alerts instructing them to restart their systems due to high memory usage. This disruption, linked to a memory management issue within Outlook, has also caused login problems that prevent users from accessing their accounts.

Investigating the Cause: High Resource Usage and Authentication Failures

Microsoft's incident report, tracked as MO907654, provides insight into the depth of the issue. The company is gathering data from customers affected by these app crashes, examining system telemetry and memory dumps to pinpoint the source of the problem. The bug appears to stem from memory management issues, which have escalated to cause login failures and unstable system performance for affected users.

While the company is reviewing telemetry data to better understand the network and authentication issues, it is also working on developing a mitigation strategy to resolve the Outlook bug. This proactive approach ensures that both the desktop version of Outlook and the Outlook Web App (OWA) will be stabilized as swiftly as possible.

Broader Microsoft 365 Disruptions

Interestingly, this Outlook bug has caused disruptions that extend beyond just the email client itself. Several users have reported that it also affects their ability to log into other Microsoft 365 services. As the company analyzes data, including networking specifics and authentication-related issues in Europe, it is considering how this could potentially impact the wider Microsoft 365 ecosystem.

This investigation bears similarities to previous outages Microsoft has experienced, such as the Azure outage in August 2024, which affected customers in North and Latin America. These incidents highlight the critical need for robust digital threat scoring and risk evaluation to prevent service outages that could be exploited for brand impersonation defense or compromised data tracking.

Conclusion

As Microsoft works diligently to investigate and resolve this issue, it’s clear that this Outlook bug has significant implications for users globally. From system crashes to high memory usage, and even blocking access to other Microsoft 365 services, the scope of the problem underscores the importance of monitoring potential vulnerabilities in digital infrastructure.

Microsoft's current investigation is a reminder that even industry giants must be vigilant in their online risk evaluation efforts. Employing proactive strategies like digital footprint analysis and darknet monitoring services can help organizations detect and mitigate threats that may emerge from such large-scale disruptions.

As the company gathers more data and formulates a fix, users can expect further updates on how Microsoft plans to address the widespread instability in its Outlook client and other affected services.

About Foresiet!

Foresiet is the pioneering force in digital security solutions, offering the first integrated Digital Risk Protection SaaS platform. With 24x7x365 dark web monitoring and proactive threat intelligence, Foresiet safeguards against data breaches and intellectual property theft. Our robust suite includes brand protection, takedown services, and supply chain assessment, enhancing your organization's defense mechanisms. Attack surface management is a key component of our approach, ensuring comprehensive protection across all vulnerable points. Compliance is assured through adherence to ISO27001, NIST, GDPR, PCI, SOX, HIPAA, SAMA, CITC, and Third Party regulations. Additionally, our advanced antiphishing shield provides unparalleled protection against malicious emails. Trust Foresiet to empower your organization to navigate the digital landscape securely and confidently.