Description

Improper limitation of a pathname to a restricted directory ('path traversal') in Microsoft Teams for Android allows an unauthorized attacker to execute code over a network.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-08-11T17:18:56.117Z",
  "pubdate": "2026-08-11T17:18:56.117Z",
  "executiveSummary": "An improper limitation of a pathname to a restricted directory vulnerability, commonly categorized as path traversal, exists within Microsoft Teams for Android. This security flaw allows an unauthorized remote attacker to achieve arbitrary code execution over a network. The vulnerability impacts the Microsoft Teams application on the Android platform, posing severe risk implications such as complete compromise of application integrity, unauthorized access to sensitive user data, and potential lateral movement within the device context. The attack capabilities involve remote exploitation without requiring complex prior authentication or privileged access within the application domain, provided the network vector is accessible. Exploitation requirements leverage inherent weaknesses in how file system pathways and directory boundaries are validated during data ingestion or processing routines within the vulnerable software. Successful exploitation undermines the fundamental security sandbox of the affected mobile application, exposing users to malicious payloads delivered across the network.",
  "technicalDetails": "The root cause of the vulnerability stems from insufficient input validation and sanitization of file paths processed by Microsoft Teams for Android. Specifically, the application fails to adequately restrict pathnames to designated restricted directories, enabling directory traversal sequences (such as dot-dot-slash patterns) to bypass intended containment mechanisms. The vulnerable component resides within the file handling and storage management routines of the Microsoft Teams application package. Exploitation occurs over a network vector where an unauthorized remote attacker transmits a maliciously crafted payload containing directory traversal directives designed to target specific internal file paths or execution contexts. As the application processes the incoming data or file transfer, the lack of robust pathname canonicalization allows the attacker to escape the restricted directory and write or access arbitrary files within the application's writable storage space or execution path. By leveraging this path traversal capability, the attacker can overwrite critical application binaries, libraries, or configuration files with malicious code. When the application subsequently executes or loads these compromised components, the injected payload executes with the privilege level of the Microsoft Teams process. The authentication requirements are minimal or absent for the network-based trigger, and no prior privileged access within the application is necessary to initiate the attack flow. The post-exploitation impact includes arbitrary code execution within the context of the mobile application, potentially leading to unauthorized data exfiltration, session hijacking, persistent compromise of the Teams client, and further exploitation of the underlying Android operating system depending on existing sandbox boundaries and permission sets."
}