CVE-2026-65769 in Teams
Summary
by MITRE • 08/12/2026
Exposure of sensitive information to an unauthorized actor in Microsoft Teams Mobile allows an unauthorized attacker to disclose information over a network.
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Analysis
by VulDB Data Team • 08/12/2026
This vulnerability represents a critical security flaw in Microsoft Teams mobile applications that enables unauthorized disclosure of sensitive information through network communications. The exposure occurs when the mobile client fails to properly implement access controls or encryption mechanisms, allowing malicious actors to intercept and access data that should remain protected within the secure communication environment. Such vulnerabilities typically arise from insufficient input validation, improper authentication checks, or weak session management protocols that leave channels open for unauthorized data exfiltration.
The technical implementation of this weakness likely involves inadequate protection of sensitive data flows within the mobile application's network stack. Attackers can exploit this vulnerability by leveraging man-in-the-middle techniques or by compromising network intermediaries to capture communications between the mobile client and Microsoft Teams servers. The flaw may manifest through improper handling of API calls, insufficient TLS configuration, or failure to validate network connections before transmitting sensitive information. This type of vulnerability aligns with CWE-200, which specifically addresses the exposure of sensitive information to unauthorized actors, and represents a fundamental breakdown in the principle of least privilege within mobile security implementations.
The operational impact of this vulnerability extends beyond simple data leakage to encompass potential compromise of corporate communications, user privacy violations, and breach of confidential business information. Organizations relying on Microsoft Teams for secure collaboration may experience unauthorized access to sensitive meetings, chat conversations, file transfers, and user credentials that are transmitted through the vulnerable mobile client. The attack surface is particularly concerning given that mobile devices often operate in less controlled network environments such as public Wi-Fi networks or unsecured corporate networks where interception attacks are more prevalent. This vulnerability directly impacts the confidentiality aspect of the CIA triad and can lead to serious compliance violations under regulations such as gdpr, hipaa, and soc 2.
Mitigation strategies should focus on immediate patch management for affected Microsoft Teams mobile applications while implementing network monitoring solutions to detect anomalous traffic patterns that may indicate data exfiltration attempts. Organizations should enforce mandatory secure network configurations including proper TLS certificate validation and implement network segmentation to isolate sensitive communications. Additional protective measures include deploying mobile device management solutions that can enforce security policies, regularly auditing network traffic for suspicious activities, and conducting penetration testing to identify similar vulnerabilities in the broader communication infrastructure. The remediation process must also include comprehensive staff training on recognizing potential security threats and understanding the importance of secure communication practices within enterprise environments.