CVE-2025-53774 is a command injection vulnerability classified under CWE-77, affecting Microsoft 365 Copilot's Business Chat component. The flaw arises from improper neutralization of special elements in user-supplied inputs, allowing attackers to inject and execute arbitrary commands on the underlying system. This vulnerability can be exploited remotely without authentication or user interaction, increasing its risk profile. The impact primarily concerns confidentiality and integrity, as attackers could potentially access sensitive business chat data or manipulate chat responses, but it does not directly impact system availability. The vulnerability was published on August 7, 2025, with a CVSS v3.1 base score of 6.5, indicating medium severity. No affected versions are explicitly listed, and no patches have been released at the time of this report. There are no known exploits in the wild, but the presence of this vulnerability in a widely used enterprise collaboration tool makes it a significant concern. The vulnerability could be leveraged to extract sensitive corporate information or disrupt business communications by injecting malicious commands into the chat environment. Given the integration of Microsoft 365 Copilot in many enterprise workflows, this vulnerability poses a risk to organizations relying on this AI-powered chat assistant for business operations.

For European organizations, this vulnerability could lead to unauthorized disclosure of sensitive business information shared within Microsoft 365 Copilot's Business Chat. Attackers exploiting this flaw could execute arbitrary commands, potentially accessing confidential data or altering chat outputs, undermining data integrity. This could result in intellectual property theft, exposure of strategic communications, or manipulation of business decisions based on corrupted chat data. Although availability is not directly impacted, the loss of confidentiality and integrity could have severe operational and reputational consequences. Organizations in sectors with high regulatory requirements for data protection, such as finance, healthcare, and government, face increased compliance risks. The remote and unauthenticated nature of the exploit increases the attack surface, especially for organizations with exposed or poorly segmented networks. The lack of a patch at present means organizations must rely on interim mitigations to reduce risk.

1. Monitor official Microsoft security advisories closely and apply patches immediately once released for Microsoft 365 Copilot's Business Chat. 2. Implement strict network segmentation and firewall rules to limit access to Microsoft 365 Copilot services, especially from untrusted networks. 3. Employ advanced threat detection and monitoring solutions to identify anomalous command execution patterns or unusual chat activity indicative of exploitation attempts. 4. Enforce least privilege access controls on Microsoft 365 accounts and restrict permissions related to Copilot Business Chat usage. 5. Educate users and administrators about the risks of command injection and encourage reporting of suspicious chat behavior. 6. Where possible, disable or restrict the use of Business Chat features until a patch is available. 7. Use input validation and sanitization controls at the application layer if custom integrations with Copilot exist. 8. Review and audit logs regularly for signs of unauthorized command execution or data exfiltration attempts.