Microsoft has identified a critical remote code execution (RCE) vulnerability in its Teams software, designated as CVE-2025-53783, during the August 2025 Patch Tuesday updates. This heap-based buffer overflow vulnerability allows unauthorized attackers to manipulate user messages and data through network code execution. It has a CVSS 3.1 score of 7.5, categorized as “Important.” Exploitation requires user interaction, such as clicking a malicious link or opening a specially crafted file. Microsoft has issued a fix and recommends users implement the latest security updates. There have been no public disclosures or active exploitation of this vulnerability, and its likelihood of exploitation is assessed as “Less Likely.” The vulnerability is part of a broader update addressing 107 flaws, including a zero-day vulnerability in Windows Kerberos. Security experts advise organizations using Microsoft Teams to prioritize the August 2025 security updates due to the serious risk of data compromise.