Summaryinfo

A vulnerability labeled as problematic has been found in activestorage Gem on Rails. Affected is an unknown function. The manipulation results in allocation of resources. This vulnerability was named CVE-2026-33658. The attack may be performed from remote. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as problematic, was found in activestorage Gem on Rails. Affected is an unknown part. The manipulation with an unknown input leads to a allocation of resources vulnerability. CWE is classifying the issue as CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. This is going to have an impact on availability. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2026-33658 since 03/23/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1499.

The vulnerability scanner Nessus provides a plugin with the ID 304159 (Linux Distros Unpatched Vulnerability : CVE-2026-33658), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 7.2.3.1, 8.0.4.1 or 8.1.2.1 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (304159). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Name

• activestorage Gem

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Discussion