CVE-2026-34829 - High Severity Vulnerability
Vulnerable Library - rack-2.2.22.gem
Rack provides a minimal, modular and adaptable interface for developing
web applications in Ruby. By wrapping HTTP requests and responses in
the simplest way possible, it unifies and distills the API for web
servers, web frameworks, and software in between (the so-called
middleware) into a single method call.
Library home page: https://rubygems.org/gems/rack-2.2.22.gem
Path to dependency file: /Gemfile.lock
Path to vulnerable library: /tmp/containerbase/cache/.ruby/cache/rack-2.2.22.gem
Dependency Hierarchy:
- ❌ rack-2.2.22.gem (Vulnerable Library)
Found in base branch: master
Vulnerability Details
Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Multipart::Parser only wraps the request body in a BoundedIO when CONTENT_LENGTH is present. When a multipart/form-data request is sent without a Content-Length header, such as with HTTP chunked transfer encoding, multipart parsing continues until end-of-stream with no total size limit. For file parts, the uploaded body is written directly to a temporary file on disk rather than being constrained by the buffered in-memory upload limit. An unauthenticated attacker can therefore stream an arbitrarily large multipart file upload and consume unbounded disk space. This results in a denial of service condition for Rack applications that accept multipart form data. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.
Publish Date: 2026-04-02
URL: CVE-2026-34829
CVSS 3 Score Details (7.5)
Base Score Metrics:
- Exploitability Metrics:
- Attack Vector: Network
- Attack Complexity: Low
- Privileges Required: None
- User Interaction: None
- Scope: Unchanged
- Impact Metrics:
- Confidentiality Impact: None
- Integrity Impact: None
- Availability Impact: High
For more information on CVSS3 Scores, click here.
Suggested Fix
Type: Upgrade version
Origin: GHSA-8vqr-qjwx-82mw
Release Date: 2026-04-02
Fix Resolution: rack - 3.2.6,rack - 3.1.21,rack - 2.2.23
Step up your Open Source Security Game with Mend here
CVE-2026-34829 - High Severity Vulnerability
Rack provides a minimal, modular and adaptable interface for developing web applications in Ruby. By wrapping HTTP requests and responses in the simplest way possible, it unifies and distills the API for web servers, web frameworks, and software in between (the so-called middleware) into a single method call.
Library home page: https://rubygems.org/gems/rack-2.2.22.gem
Path to dependency file: /Gemfile.lock
Path to vulnerable library: /tmp/containerbase/cache/.ruby/cache/rack-2.2.22.gem
Dependency Hierarchy:
Found in base branch: master
Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Multipart::Parser only wraps the request body in a BoundedIO when CONTENT_LENGTH is present. When a multipart/form-data request is sent without a Content-Length header, such as with HTTP chunked transfer encoding, multipart parsing continues until end-of-stream with no total size limit. For file parts, the uploaded body is written directly to a temporary file on disk rather than being constrained by the buffered in-memory upload limit. An unauthenticated attacker can therefore stream an arbitrarily large multipart file upload and consume unbounded disk space. This results in a denial of service condition for Rack applications that accept multipart form data. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.
Publish Date: 2026-04-02
URL: CVE-2026-34829
Base Score Metrics:
- Exploitability Metrics:
- Attack Vector: Network
- Attack Complexity: Low
- Privileges Required: None
- User Interaction: None
- Scope: Unchanged
- Impact Metrics:
- Confidentiality Impact: None
- Integrity Impact: None
- Availability Impact: High
For more information on CVSS3 Scores, click here.Type: Upgrade version
Origin: GHSA-8vqr-qjwx-82mw
Release Date: 2026-04-02
Fix Resolution: rack - 3.2.6,rack - 3.1.21,rack - 2.2.23
Step up your Open Source Security Game with Mend here