CVE-2026-42533: Critical NGINX Map Regex Flaw Can Trigger Heap Buffer Overflow and Possible RCE

Key Takeaways

• F5 has disclosed multiple NGINX vulnerabilities, with CVE-2026-42533 standing out as a critical heap buffer overflow in NGINX's handling of the map directive.
• The flaw is a heap buffer overflow in NGINX’s handling of the map directive when regular expression matching references regex variables in a specific.
• In vulnerable deployments, a remote unauthenticated attacker can send crafted HTTP requests that corrupt memory in the NGINX worker process, potential.