Activestorage: Rails Active Storage has a possible DoS vulnerability in proxy mode via multi-range requests
Affects activestorageSource GCVE Database
Not known to be exploited · CVSS 2.3 Low : upgrade to 8.1.2.1 when convenient.
Data as of 27 Oct 2026, 00:07 UTC
- Patch
- Available – fixed in 8.1.2.1, 8.0.4.1, 7.2.3.1
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:UExploitation evidence
Disclosed: evidence found.
CVE published 26 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade activestorage to 8.1.2.1; activestorage to 8.0.4.1; activestorage to 7.2.3.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| RubyGemsactivestorage | Affected
| Fixed in
|
| RubyGemsactivestorage | Affected
| Fixed in
|
| RubyGemsactivestorage | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
### 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. ### Releases The fixed releases are available at the normal locations. ### Credit This issue was responsibly reported by Hackerone researcher [thwin_htet](https://hackerone.com/thwin_htet).
References
- github.com/rails/rails/security/advisories/GHSA-p9fm-f462-ggrg (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-33658 (opens in a new tab)
- github.com/rails/rails (opens in a new tab)
- github.com/rails/rails/releases/tag/v7.2.3.1 (opens in a new tab)
- github.com/rails/rails/releases/tag/v8.0.4.1 (opens in a new tab)
- github.com/rails/rails/releases/tag/v8.1.2.1 (opens in a new tab)
- github.com/rubysec/ruby-advisory-db/blob/master/gems/activestorage/CVE-2026-33658.yml (opens in a new tab)