CVE-2026-33174
High
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, 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.
SeverityHigh
CVSS7.5
Exploit probability—
ProductRails
PublishedMar 24, 2026
First seenMar 24, 2026
Weakness typeCWE-789CWE-789
How to fix
Update
- rubyonrails rails7.2.3.1, 8.0.4.1, 8.1.2.1 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| rubyonrails rails | v < 7.2.3.1, 8.0.0 ≤ v < 8.0.4.1, 8.1.0 ≤ v < 8.1.2.1 | 7.2.3.1, 8.0.4.1, 8.1.2.1 |
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