Rails Active Storage has a possible DoS vulnerability in proxy mode via multi-range requests
Published Mar 26, 2026 · Updated Oct 23, 2026 · Also known as GHSA-p9fm-f462-ggrg
Original summary
Normalized public record · Updated Oct 23, 2026
Rails Active Storage has a possible DoS vulnerability in proxy mode via multi-range requests
Publisher and source text is retained separately from QFinch interpretation.
QFinch assessment
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.
Potential impact
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.
Evidence: public source recordsAffected products
| Affected package, product or range | Fix status |
|---|---|
| Consult the referenced vendor advisory for affected versions. | Consult source advisory |
Matching a version is only one part of assessing exposure. QFinch has not assessed your environment on this public page.
Remediation
Apply the vendor-supported fixed release or mitigation, then verify the affected component is no longer reachable.
- Confirm the affected product and reachable code path exist in your environment.
- Apply the vendor-supported patch or mitigation from the primary advisory.
- Rescan the exact deployed revision and retain verification evidence.
Evidence coverage
- SSVC priority
- LOW
- Confidence
- Not available
- Aliases
- GHSA-p9fm-f462-ggrg
Scores appear only when corresponding evidence exists. Missing data is never interpreted as zero risk.
Sources and record history
Record history
Published Mar 26, 2026 · Last refreshed Oct 23, 2026