CVE-2026-34826
rack: Rack: Denial of Service via malicious HTTP Range header
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · April 3, 2026
Updated · June 30, 2026
Description
A flaw was found in Rack. A remote attacker can exploit this by sending a specially crafted HTTP Range header containing numerous small, overlapping byte ranges. This can cause disproportionate consumption of CPU, memory, I/O, and bandwidth resources. The result is a Denial of Service (DoS) condition in Rack file-serving paths that process multipart byte range responses.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
CVSS / CWE
CVSS 3.1 · 5.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
CWE-770 · Allocation of Resources Without Limits or Throttling