CVE-2026-34826
Rack: Unbounded Range Count in get_byte_ranges Enables DoS
Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Utils.get_byte_ranges parses the HTTP Range header without limiting the number of individual byte ranges. Although the existing fix for CVE-2024-26141 rejects ranges whose total byte coverage exceeds the file size, it does not restrict the count of ranges. An attacker can supply many small overlapping ranges such as 0-0,0-0,0-0,... to trigger disproportionate CPU, memory, I/O, and bandwidth consumption per request. This results in a denial of service condition in Rack file-serving paths that process multipart byte range responses. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.
| CWE | CWE-400 CWE-770 |
| Vendor | rack |
| Product | rack |
| Published | Apr 2, 2026 |
| Last Updated | Apr 3, 2026 |
Get instant alerts for rack rack
Be the first to know when new medium vulnerabilities affecting rack rack are published — delivered to Slack, Telegram or Discord.
CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L