The National Security Agency recently discovered a “critical vulnerability” in Microsoft Corp’s Windows operating systems that could leave them at risk for cyber intrusions. The NSA informed Microsoft of the vulnerability and encouraged the company to expedite the development of the patches in order to mitigate the risk of cyber intrusions.

The NSA’s past policy was not to publicly share the discovery of such vulnerabilities. However, in an effort to “build trust and encourage patching” within the cybersecurity community, the NSA disclosed the vulnerability publicly.

Microsoft has already announced the patch, and that there were no intrusions as a result of the vulnerability.