CVE-2025-59272 is a command injection vulnerability categorized under CWE-77, found in Microsoft 365 Copilot's Business Chat feature. The vulnerability stems from improper neutralization of special elements used in commands, which allows an attacker to inject arbitrary commands into the system. Specifically, the Business Chat component fails to adequately sanitize or validate user-supplied inputs before incorporating them into command execution contexts. This can lead to execution of unintended commands, potentially exposing sensitive information. The CVSS 3.1 base score is 6.5 (medium severity), reflecting that the attack vector is network-based (AV:N), requires no privileges (PR:N), but does require user interaction (UI:R). The scope is unchanged (S:U), and the impact is high on confidentiality (C:H) but none on integrity or availability (I:N/A:N). The exploitability is rated as 'unproven' (E:U), with official remediation not yet available (RL:O) and the report confirmed (RC:C). No known exploits exist in the wild at this time. The vulnerability was reserved in early September 2025 and published in October 2025. Given that Microsoft 365 Copilot is a cloud-based AI assistant integrated into business chat workflows, this vulnerability could be exploited via crafted inputs in chat interactions that trigger command injection, potentially leaking confidential data or executing unauthorized commands within the context of the chat service. The lack of patches means organizations must rely on interim mitigations and monitoring until updates are released.

For European organizations, the primary impact of CVE-2025-59272 is the potential exposure of confidential information through command injection in a widely used productivity tool. Since Microsoft 365 Copilot Business Chat is integrated into enterprise workflows, attackers exploiting this vulnerability could access sensitive business data, intellectual property, or personal information. The vulnerability does not affect data integrity or system availability directly, but confidentiality breaches could lead to regulatory non-compliance under GDPR, reputational damage, and financial losses. Organizations in sectors such as finance, healthcare, and government, which heavily rely on Microsoft 365 services, are particularly at risk. The requirement for user interaction means phishing or social engineering could be used to trigger the exploit. The absence of known exploits currently provides a window for proactive defense, but the medium severity score indicates that the threat should not be underestimated. The cloud-based nature of the product means that attacks could originate remotely, increasing the attack surface for European enterprises using these services.

1. Implement strict input validation and sanitization policies on all user inputs interacting with Microsoft 365 Copilot Business Chat, especially in custom integrations or extensions. 2. Educate users to recognize and avoid interacting with suspicious or unexpected chat prompts that could trigger command injection. 3. Monitor network and application logs for unusual command execution patterns or anomalous chat activity that could indicate exploitation attempts. 4. Employ endpoint detection and response (EDR) tools to detect suspicious behaviors related to command execution stemming from chat interactions. 5. Restrict permissions and access controls on Microsoft 365 Copilot Business Chat to minimize exposure and limit the scope of potential command injection impact. 6. Stay informed on Microsoft’s security advisories and apply patches or updates immediately once available. 7. Consider deploying web application firewalls (WAFs) or security gateways that can detect and block injection attempts targeting chat interfaces. 8. Conduct regular security assessments and penetration testing focusing on the integration points of Microsoft 365 Copilot Business Chat within enterprise environments.