Microsoft Teams RCE Vulnerability: Critical Flaw Allows Message Manipulation

Microsoft has disclosed a critical remote code execution (RCE) vulnerability in its Teams collaboration software as part of its August 2025 Patch Tuesday updates. Identified as CVE-2025-53783, this flaw could enable unauthorized attackers to read, write, and delete user messages and data by executing code over a network.


The vulnerability is a heap-based buffer overflow, which allows an application to store data beyond its allocated memory space. An attacker could exploit this weakness to overwrite critical data or execute malicious code within the Teams application.


Microsoft assigned the vulnerability a CVSS 3.1 score of 7.5, categorizing it as “Important.” Exploiting this flaw requires a high degree of complexity and user interaction, such as clicking a malicious link or opening a specially crafted file. As of now, the vulnerability has not been publicly disclosed or actively exploited, with Microsoft assessing the likelihood of exploitation as “Less Likely.”