Vulnerability 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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Rack | Rack | < 2.2.23 |
Related Weaknesses (CWE)
References
- https://github.com/rack/rack/security/advisories/GHSA-x8cg-fq8g-mxfxVendor AdvisoryMitigation
FAQ
What is CVE-2026-34826?
CVE-2026-34826 is a vulnerability with a CVSS score of 5.3 (MEDIUM). 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...
How severe is CVE-2026-34826?
CVE-2026-34826 has been rated MEDIUM with a CVSS base score of 5.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-34826?
Check the references section above for vendor advisories and patch information. Affected products include: Rack Rack.