CVE-2026-33658

Publication date 26 March 2026

Last updated 10 July 2026

Ubuntu priority

Cvss 3 Severity Score

Description

Active Storage allows users to attach cloud and local files in Rails applications. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 Active Storage's proxy controller does not limit the number of byte ranges in an HTTP Range header. A request with thousands of small ranges causes disproportionate CPU usage compared to a normal request for the same file, possibly resulting in a DoS vulnerability. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
rails	26.04 LTS resolute	Needs evaluation
	25.10 questing	Ignored end of life, was needs-triage
	24.04 LTS noble	Needs evaluation
	22.04 LTS jammy	Needs evaluation
	20.04 LTS focal	Needs evaluation
	18.04 LTS bionic	Needs evaluation
	16.04 LTS xenial	Ignored end of ESM support, was needs-triage

Notes

seth-arnold

In Oneiric-Saucy, rails package is just for transition; The rails package contains actual code from vivid onward

Severity score breakdown

CVSS version:

Base score 2.3 · Low

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	Low
Attack requirements	Present
Privileges required	Low
User interaction	None
Vulnerable system - Confidentiality impact	None
Vulnerable system - Integrity impact	None
Vulnerable system - Availability impact	High
Subsequent system - Confidentiality impact	None
Subsequent system - Integrity impact	None
Subsequent system - Availability impact	None

Scores

Parameter	Value
Base score	2.3 · Low
Base + Threat score	-
Base + Environmental score	-
Base + Threat + Environmental score	-

Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U

Base score 6.5 · Medium