vulnerability

Ruby on Rails Ruby on Rails: CVE-2026-33169: Uncontrolled Resource Consumption

Severity
5
CVSS
(AV:N/AC:L/Au:N/C:N/I:N/A:P)
Published
Mar 24, 2026
Added
Apr 7, 2026
Modified
May 6, 2026

Description

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.

Solution

ruby-on-rails-upgrade-latest

References

    Title
    Rapid7 Labs

    2026 Global Threat Landscape Report

    The predictive window has collapsed. Exploitation follows disclosure in days. See how attackers are accelerating and how to stay ahead.