CVE-2026-33658
Rails Active Storage has a possible DoS vulnerability in proxy mode via multi-range requests
6.5
MEDIUM
CVSS 3.1
EPSS 0.02%
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.
How to fix CVE-2026-33658
To remediate CVE-2026-33658, upgrade the affected package to a fixed version below.
- —no fix listed
- —upgrade to 8.1.2.1 or later
Is CVE-2026-33658 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (2)
- from 0
- >= 8.1.0, < 8.1.2.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | 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 |
| osv | CVSS 3.1 | MEDIUM6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |