CVE-2026-42945

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module. This vulnerability exists when the rewrite directive is followed by a rewrite, if, or set directive and an unnamed Perl-Compatible Regular Expression (PCRE) capture (for example, $1, $2) with a replacement string that includes a question mark (?). An unauthenticated attacker along with conditions beyond its control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR.  Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

• F5 Dos

  APP
  F5
  4.8.04.3.0 – 4.7.0

• F5 nginx Gateway Fabric

  APP
  F5
  1.3.0 – 1.6.22.0.0 – 2.5.1

• F5 nginx Ingress Controller

  APP
  F5
  5.0.0 – 5.4.13.5.0 – 3.7.24.0.0 – 4.0.1

• F5 nginx Instance Manager

  APP
  F5
  2.16.0 – 2.21.1

• F5 nginx Open Source

  APP
  F5
  0.6.27 – 1.30.0

• F5 nginx Plus

  APP
  F5
  r32 – r36

• F5 Waf

  APP
  F5
  4.9.0 – 4.16.05.1.0 – 5.8.05.9.0 – 5.12.1