CVE-2025-49737 is a high-severity race condition vulnerability (CWE-362) identified in Microsoft Teams for Mac, specifically affecting version 1.0.0.0. The flaw arises from improper synchronization during concurrent execution of shared resources within the application. This race condition allows an authorized local attacker—someone with limited privileges on the affected Mac system—to exploit the timing window where shared resources are accessed or modified without adequate locking or atomic operations. By doing so, the attacker can elevate their privileges locally, potentially gaining higher system rights than originally granted. The vulnerability impacts confidentiality, integrity, and availability, as it can lead to unauthorized access to sensitive data, modification of system or application state, and disruption of normal operations. The CVSS 3.1 score of 7.0 reflects a high severity, with an attack vector limited to local access (AV:L), requiring high attack complexity (AC:H), low privileges (PR:L), and no user interaction (UI:N). The scope remains unchanged (S:U), but the impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H). No known exploits are currently reported in the wild, and no patches have been linked yet, indicating that mitigation may require vendor updates or workarounds. The vulnerability was reserved in early June 2025 and published in July 2025, suggesting it is a recent discovery.

For European organizations, this vulnerability poses a significant risk, especially for enterprises and institutions relying on Microsoft Teams for Mac as a core collaboration tool. The ability for a local attacker to elevate privileges can lead to unauthorized access to corporate communications, sensitive files, and internal resources shared via Teams. This could facilitate lateral movement within networks, data exfiltration, or sabotage of collaboration infrastructure. Given the widespread adoption of Microsoft Teams across European public and private sectors, including government agencies, financial institutions, and healthcare providers, exploitation could disrupt critical services and compromise confidential information. The local attack vector means that threat actors would need initial access to the endpoint, which could be achieved through phishing, malware, or insider threats. The high attack complexity somewhat limits mass exploitation but does not eliminate targeted attacks against high-value targets. The lack of user interaction requirement increases the risk once local access is obtained. Overall, the vulnerability could undermine trust in communication platforms and impact compliance with data protection regulations such as GDPR if exploited.

European organizations should prioritize the following specific mitigation steps: 1) Immediately inventory and identify all Mac endpoints running Microsoft Teams version 1.0.0.0. 2) Restrict local user permissions to the minimum necessary, enforcing strict endpoint access controls and limiting administrative privileges to reduce the risk of privilege escalation. 3) Monitor and audit local user activities on Mac devices for unusual behavior indicative of exploitation attempts, such as unexpected privilege escalations or process anomalies. 4) Implement endpoint detection and response (EDR) solutions capable of detecting race condition exploitation patterns or suspicious concurrent resource access. 5) Until an official patch is released, consider applying application-level workarounds such as disabling or restricting features that involve shared resource concurrency if feasible. 6) Educate users on the risks of local compromise vectors and enforce strong endpoint security hygiene, including regular updates of macOS and security software to reduce initial compromise likelihood. 7) Engage with Microsoft support channels to obtain timely patches or mitigations once available and plan for rapid deployment across the organization. 8) For critical environments, consider isolating Mac endpoints or limiting their network access to reduce potential lateral movement post-exploitation.