CVE-2026-34826: medium-severity vulnerability in rack
Rack: Unbounded Range Count in get_byte_ranges Enables DoS
Published · Updated
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.3epss 0.4%
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:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Affected products
rack · rackRelated CVEs — rack
In the same product, most dangerous first.
CVE-2024-25126MEDIUMRack ReDos in content type parsing (2nd degree polynomial)EPSS 35.4%CVE-2019-16782MEDIUMPossible Information Leak / Session Hijack Vulnerability in RackEPSS 3.7%CVE-2024-26146MEDIUMPossible Denial of Service Vulnerability in Rack Header ParsingEPSS 2.0%CVE-2024-26141MEDIUMPossible DoS Vulnerability with Range Header in RackEPSS 1.6%CVE-2025-46727HIGHUnbounded-Parameter DoS in Rack::QueryParserEPSS 1.2%CVE-2025-25184MEDIUMPossible Log Injection in Rack::CommonLoggerEPSS 1.2%