CVE-2026-56434 NGINX ngx_http_ssi_module vulnerability

NGINX Plus and NGINX Open Source have a vulnerability in the ngxhttpssimodule module. This vulnerability may exist when the Server-Side Includes SSI, proxypass, and proxybuffering off directives are configured. With this configuration, an unauthenticated attacker with man-in-the-middle MITM abili...

CVE-2026-56434

Summary: CVE-2026-56434 affects the nginx ngx_http_ssi_module in NGINX Plus and NGINX Open Source when SSI, proxy_pass, and proxy_buffering are configured off. An unauthenticated attacker with MITM control over upstream responses can trigger a heap buffer over-read in the nginx worker process, po...