Uncontrolled Memory Allocation in Ruby on Rails - CVE-2026-33174

Vulnerability identifier: #VU124275

CSH Severity: Medium

CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-33174

CWE-ID: CWE-789

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to ucontrolled memory allocation in Active Storage proxy mode. A remote attacker can cause a denial of service (DoS) condition on the target system.

Ruby on Rails
Fedora
rubygem-actioncable
rubygem-actionmailbox
rubygem-actionmailer
rubygem-actionpack
rubygem-actiontext
rubygem-actionview
rubygem-activejob
rubygem-activemodel
rubygem-activerecord
rubygem-activestorage
rubygem-activesupport
rubygem-rails
rubygem-railties

Install updates from vendor's website.

Ruby on Rails - addressed in versions 7.2.3.1, 8.0.4.1, 8.1.2.1
rubygem-actioncable - update to 8.1.3.1-1.fc45
rubygem-actionmailbox - update to 8.1.3.1-1.fc45
rubygem-actionmailer - update to 8.1.3.1-1.fc45
rubygem-actionpack - update to 8.1.3.1-1.fc45
rubygem-actiontext - update to 8.1.3.1-1.fc45
rubygem-actionview - update to 8.1.3.1-1.fc45
rubygem-activejob - update to 8.1.3.1-1.fc45
rubygem-activemodel - update to 8.1.3.1-1.fc45
rubygem-activerecord - update to 8.1.3.1-1.fc45
rubygem-activestorage - update to 8.1.3.1-1.fc45
rubygem-activesupport - update to 8.1.3.1-1.fc45
rubygem-rails - update to 8.1.3.1-1.fc45
rubygem-railties - update to 8.1.3.1-2.fc45

• https://github.com/rails/rails/security/advisories/GHSA-r46p-8f7g-vvvg

• Multiple vulnerabilities in Ruby on Rails
• Fedora 45 update for rubygem-actioncable, rubygem-actionmailbox, rubygem-actionmailer, rubygem-actionpack, rubygem-actiontext, rubygem-actionview, rubygem-activejob, rubygem-activemodel, rubygem-activerecord, rubygem-activestorage, rubygem-activesupport,