Web Server | Breaking Cybersecurity News | The Hacker News

Cybersecurity researchers have discovered a remote denial-of-service exploit that affects major web servers, including NGINX, Apache HTTPD, Microsoft IIS, Envoy, and Cloudflare Pingora. The vulnerability has been codenamed HTTP/2 Bomb by Calif. "The vulnerable behavior exists in each server's default HTTP/2 configuration," the company said, adding it was discovered by OpenAI Codex by chaining together two known techniques: a compression bomb and a Slowloris -style hold. "The bomb targets HPACK, HTTP/2's header compression scheme: one byte on the wire becomes one full header allocation on the server, repeated thousands of times per request," Calif added. "The hold is a zero-byte flow-control window that keeps the server from ever freeing any of it." HPACK is a dedicated header compression algorithm for HTTP/2 used for compressing request and response metadata using Huffman encoding that results in an average reduction of 30% in header siz...

Cybersecurity researchers have disclosed multiple security vulnerabilities impacting NGINX Plus and NGINX Open, including a critical flaw that remained undetected for 18 years. The vulnerability, discovered by depthfirst , is a heap buffer overflow issue impacting ngx_http_rewrite_module (CVE-2026-42945, CVSS v4 score: 9.2) that could allow an attacker to achieve remote code execution or cause a denial-of-service (DoS) with crafted requests. It has been codenamed NGINX Rift . "NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module," F5 said in an advisory released Wednesday. "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 vulnerabili...