CVE-2026-42055

NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_proxy_v2_module and ngx_http_grpc_module modules. This vulnerability exists when the proxy_http_version to 2 or grpc_pass directives are used to proxy HTTP/2 traffic, the ignore_invalid_headers directive is set to off, and the large_client_header_buffers directive size is larger than 2 megabytes. A remote, unauthenticated attacker, along with conditions beyond their control, could send large headers while creating an upstream request. This may cause a heap-based 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
  4.9.04.3.0 – 4.7.0

• F5 nginx Gateway Fabric

  APP
  F5
  1.3.0 – 1.6.22.0.0 – 2.6.3

• F5 nginx Ingress Controller

  APP
  F5
  3.5.0 – 3.7.24.0.0 – 4.0.15.0.0 – 5.5.0

• F5 nginx Instance Manager

  APP
  F5
  2.17.0 – 2.22.0

• F5 nginx Open Source

  APP
  F5
  1.0.0 – 1.30.21.31.0 – 1.31.1

• F5 nginx Plus

  APP
  F5
  r36r33 – r36 (excl.)37.0.0.1 – 37.0.2.1 (excl.)

• F5 Waf

  APP
  F5
  4.10.0 – 4.16.05.2.0 – 5.8.05.9.0 – 5.13.1

• Red Hat Discovery

  APP
  Redhat
  all versions

• Red Hat Enterprise Linux

  OS
  Redhat
  10.08.09.0

• Red Hat Hardened Images

  APP
  Redhat
  all versions

• Red Hat Update Infrastructure

  APP
  Redhat
  5.0 – 5.2 (excl.)