Summaryinfo

A vulnerability labeled as problematic has been found in rails activestorage up to 7.2.3.1/8.0.4.1/8.1.2.1. Affected by this issue is some unknown functionality. Such manipulation leads to memory allocation. This vulnerability is listed as CVE-2026-33174. The attack may be performed from remote. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in rails activestorage up to 7.2.3.1/8.0.4.1/8.1.2.1. It has been rated as problematic. Affected by this issue is an unknown part. The manipulation with an unknown input leads to a memory allocation vulnerability. Using CWE to declare the problem leads to CWE-789. The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated. Impacted is 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, when serving files through Active Storage's proxy delivery mode, the proxy controller loads the entire requested byte range into memory before sending it. A request with a large or unbounded Range header (e.g. `bytes=0-`) could cause the server to allocate memory proportional to the file size, possibly resulting in a DoS vulnerability through memory exhaustion. 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 handled as CVE-2026-33174 since 03/17/2026. The exploitation is known to be easy. The attack may be launched remotely. There are neither technical details nor an exploit publicly available.

Upgrading to version 7.2.3.1, 8.0.4.1 or 8.1.2.1 eliminates this vulnerability. The upgrade is hosted for download at github.com. Applying the patch 2cd933c366b777f873d4d590127da2f4a25e4ba5 is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

• rails

Name

• activestorage

Version

• 7.2.3.0
• 7.2.3.1
• 8.0.4.0
• 8.0.4.1
• 8.1.2.0
• 8.1.2.1

License

• open-source

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