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

F5 disclosed multiple NGINX vulnerabilities, highlighting CVE-2026-42533 — a heap buffer overflow triggered by a specific map directive regex capture ordering that can cause worker crashes and, in some environments, enable remote code execution; no public exploit or IOCs are reported, and remediation is to apply vendor fixes and review map configurations.