Starting August 9 2025, F5 learned that a nation-state threat actor gained and maintained access to certain systems within their environment. This included access to F5’s BIG-IP product development systems and “engineering knowledge management platforms.” On October 15, F5 released knowledge base (KB) article K000154696 providing current details on the known impacts of the breach, including an acknowledgement that they have not observed further unauthorized activity and believe they have successfully contained the breach. 

In response, Tenable’s Research Special Operations (RSO) team has compiled a blog to answer Frequently Asked Questions (FAQ) regarding the security incident affecting F5. Alongside the disclosure of the security incident, F5 also released its October 2025 Quarterly Security Notification.

While there is no notice in these security advisories that any of the CVEs released on October 15 have been exploited, we strongly recommend applying all available patches.

For more information about the vulnerabilities, including the availability of patches and Tenable product coverage, please visit our blog.