CVE-2026-33658
MediumCVSS 6.5Summary
Active Storage in Rails applications allows users to attach cloud and local files. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, the proxy controller does not limit the number of byte ranges in an HTTP Range header, so a request with thousands of small ranges causes disproportionate CPU usage and may lead to a DoS vulnerability.
Risk Assessment
An attacker can send a crafted request with many ranges to exhaust server CPU resources and cause a denial of service. The risk affects Rails applications using Active Storage on versions before the patch.
Recommendation
Update Rails/Active Storage to version 8.1.2.1, 8.0.4.1, or 7.2.3.1 (or newer). Until patched, consider limiting the number of ranges in the Range header at the proxy server level.
Other vulnerabilities in Active Storage
See all- CVE-2026-33173Medium
Active Storage in Rails applications prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 allows DirectUploadsController to accept arbitrary metadata from the client and persist it on the blob. Because internal flags like identified and analyzed are stored in the same metadata hash, a direct-upload client can set them to skip MIME detection and analysis, allowing upload of arbitrary content while claiming a safe content_type and bypassing validations.
- CVE-2026-33202Critical
In Active Storage (Ruby on Rails) prior to versions 8.1.2.1, 8.0.4.1 and 7.2.3.1, DiskService#delete_prefixed passes blob keys directly to Dir.glob without escaping glob metacharacters. If a blob key contains attacker-controlled input or glob metacharacters, unintended files may be deleted from the storage directory.
- CVE-2026-33195Critical
A path traversal vulnerability in Active Storage's `DiskService#path_for` allows arbitrary file access if blob keys contain `../` sequences. Attackers can read, write, or delete files outside the storage root.
- CVE-2025-24293High
A vulnerability in Active Storage allows bypassing default security restrictions for image transformation methods, potentially leading to command injection when user-supplied input is accepted as transformation methods or parameters. The issue affects applications using Active Storage with the image_processing gem and mini_magick as the image processor.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS