tl;dr sec is a weekly newsletter covering application security, cloud security and security engineering. A concise security newsletter curating practical application-security, cloud-security, offensive-security, and engineering resources for security professionals.
It is aimed at technology professionals. It is free to read. Public sources put its audience in the 50K–100K subscriber range.
Recent issues carry sponsored placements, although a current rate card for tl;dr sec was not published at the time of research. Listing details were last verified in September 2026.