Resource Exhaustion Affecting ruby-rack package, versions *


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.48% (41st percentile)

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  • Snyk IDSNYK-UBUNTU2610-RUBYRACK-21226996
  • published18 Oct 2026
  • disclosed2 Apr 2026

Introduced: 2 Apr 2026

CVE-2026-34827  (opens in a new tab)
CWE-400  (opens in a new tab)
CWE-407  (opens in a new tab)
CWE-770  (opens in a new tab)

How to fix?

There is no fixed version for Ubuntu:26.10 ruby-rack.

NVD Description

Note: Versions mentioned in the description apply only to the upstream ruby-rack package and not the ruby-rack package as distributed by Ubuntu. See How to fix? for Ubuntu:26.10 relevant fixed versions and status.

Rack is a modular Ruby web server interface. From versions 3.0.0.beta1 to before 3.1.21, and 3.2.0 to before 3.2.6, Rack::Multipart::Parser#handle_mime_head parses quoted multipart parameters such as Content-Disposition: form-data; name="..." using repeated String#index searches combined with String#slice! prefix deletion. For escape-heavy quoted values, this causes super-linear processing. An unauthenticated attacker can send a crafted multipart/form-data request containing many parts with long backslash-escaped parameter values to trigger excessive CPU usage during multipart parsing. This results in a denial of service condition in Rack applications that accept multipart form data. This issue has been patched in versions 3.1.21 and 3.2.6.

CVSS Base Scores

version 3.1