18-Year-Old NGINX Rewrite Module Flaw Enables Unauthenticated RCE

A critical 18-year-old heap buffer overflow in NGINX's rewrite module (CVE-2026-42945) enables unauthenticated remote code execution.

• •Triggered by crafted requests with unnamed PCRE captures and question marks in rewrite directives
• •Remotely exploitable without authentication or prior access requirements
• •Allows heap corruption and RCE in NGINX worker processes, especially with ASLR disabled
• •Mitigation: use named captures instead of unnamed captures in rewrite directives

This summary was automatically generated by AI based on the original article and may not be fully accurate.