CVE-2026-33169 (Medium) detected in activesupport-8.1.1.gem

## CVE-2026-33169 - Medium Severity Vulnerability
Vulnerable Library - activesupport-8.1.1.gem

A toolkit of support libraries and Ruby core extensions extracted from the Rails framework. Rich support for multibyte strings, internationalization, time zones, and testing.

Library home page: https://rubygems.org/gems/activesupport-8.1.1.gem

Path to dependency file: /Gemfile.lock

Path to vulnerable library: /vendor/cache/activesupport-8.1.1.gem

Dependency Hierarchy:
- manageiq-style-1.5.9.gem (Root Library)
- rubocop-rails-2.29.1.gem
- :x: **activesupport-8.1.1.gem** (Vulnerable Library)

Found in base branch: master

Vulnerability Details

Active Support is a toolkit of support libraries and Ruby core extensions extracted from the Rails framework. "NumberToDelimitedConverter" uses a lookahead-based regular expression with "gsub!" to insert thousands delimiters. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, the interaction between the repeated lookahead group and "gsub!" can produce quadratic time complexity on long digit strings. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.

Publish Date: 2026-03-23

URL: CVE-2026-33169

CVSS 3 Score Details (5.3)

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: Low

For more information on CVSS3 Scores, click here.

Suggested Fix

Type: Upgrade version

Release Date: 2026-03-23

Fix Resolution: https://github.com/rails/rails.git - v8.0.4.1,https://github.com/rails/rails.git - v8.1.2.1,https://github.com/rails/rails.git - v7.2.3.1

***
Step up your Open Source Security Game with Mend [here](https://www.whitesourcesoftware.com/full_solution_bolt_github)

Start with Gemfile.lock and vendor/cache/activesupport-8.1.1.gem, then trace the rubocop-rails dependency shown in the issue. Update the dependency to a listed patched Active Support version and confirm that the vulnerable 8.1.1 version is no longer present.

Written by the indexing model from the issue text.