Critical NGINX Flaw CVE-2026-42533 Allows Remote Code Execution

The article discusses a critical vulnerability in NGINX, identified as CVE-2026-42533, which has a CVSS score of 9.2. F5 released patches to address this flaw that can allow unauthenticated attackers to execute remote code or cause server crashes through specially crafted HTTP requests. The issue impacts NGINX versions from 0.9.6 to 1.31.2 and is particularly hazardous when specific regex-based configurations are used. Temporary workarounds are suggested, such as modifying regex-based map configurations.

Researchers Mufeed VH and Maxim Dounin discovered the flaw, and security researcher Stan Shaw noted that its impact might be greater than reported, suggesting it could bypass ASLR protections and lead to remote code execution.