THE content discusses CVE-2026-42533, a critical heap overflow vulnerability in F5's NGINX rated with a CVSS score of 9.2. This vulnerability allows unauthenticated attackers to corrupt worker memory and could lead to remote code execution (RCE) due to an ASLR bypass. It affects several versions of NGINX Plus and Open Source products. Although no confirmed exploitation has occurred, a proof-of-concept has been published.
The vulnerability can be exploited through crafted requests, specifically by manipulating regex-based maps. F5 released patches on July 15, 2026, and advises users to upgrade immediately to mitigate risks.