Rack: Unbounded Range Count in get_byte_ranges Enables DoS_CVE-2026-34826

5.3 / 10

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Description

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.

Basic Information

ID CVE-2026-34826

Source GitHub_M

Published Apr 2, 2026 at 16:45

Modified Apr 3, 2026 at 18:13

Affected Product

Vendor rack

Product rack

Version < 2.2.23

Affected Versions rack rack < 2.2.23
rack rack >= 3.0.0.beta1, < 3.1.21
rack rack >= 3.2.0, < 3.2.6

CWE Classification

CWE-400 CWE-770

References

github.com /rack/rack/security/advisories/GHSA-x8cg-fq8g-mxfx

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    "published": "2026-04-02T16:45:53.964Z",
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