The vulnerability of the Rack::Utils.get_byte_ranges() function in the Ruby-based Rack web server module interface allows a attacker to cause a denial-of-service attack.

The vulnerability of the Rack::Utils.getbyteranges function in the Rack web server module interface, a programming language for Ruby, is related to an uncontrolled resource consumption. Exploiting this vulnerability could allow a malicious actor to cause service failures...

CVE-2026-34826

CVE-2026-34826 affects Rack prior to 2.2.23, 3.1.21, and 3.2.6. Rack::Utils.get_byte_ranges does not cap the number of individual byte ranges in the HTTP Range header, allowing an attacker to send many small overlapping ranges that trigger disproportionate CPU, memory, I/O, and bandwidth usage in...

Regular Expression Denial of Service (ReDoS)

Overview rack is a minimal, modular and adaptable interface for developing web applications in Ruby. By wrapping HTTP requests and responses in the simplest way possible, it unifies and distills the API for web servers, web frameworks, and software in between the so-called middleware into a singl...