CVE-2026-33174
HIGH7.5EPSS 0.02%Rails Active Storage has a possible DoS vulnerability when in proxy mode via Range requests
Published: 3/23/2026Modified: 5/13/2026
Description
### Impact When serving files through Active Storage's `Blobs::ProxyController`, the 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. ### Releases The fixed releases are available at the normal locations. ### Credit This issue was responsibly reported by Hackerone user [pirikara](https://hackerone.com/pirikara)
Affected packages (2)
- Debian/railsfrom 0
- RubyGems/activestorage>= 8.1.0.beta1, < 8.1.2.1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U |
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
References (11)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-33174
- ADVISORYhttps://security-tracker.debian.org/tracker/CVE-2026-33174
- PATCHhttps://github.com/rails/rails
- WEBhttps://github.com/rails/rails/commit/2cd933c366b777f873d4d590127da2f4a25e4ba5
- WEBhttps://github.com/rails/rails/commit/42012eaaa88dfc7d0030161b2bc8074a7bbce92a
- WEBhttps://github.com/rails/rails/commit/8159a9c3de3f27a2bcf2866b8bf9ceb9075e229b
- WEBhttps://github.com/rails/rails/releases/tag/v7.2.3.1
- WEBhttps://github.com/rails/rails/releases/tag/v8.0.4.1
- WEBhttps://github.com/rails/rails/releases/tag/v8.1.2.1
- WEBhttps://github.com/rails/rails/security/advisories/GHSA-r46p-8f7g-vvvg
- WEBhttps://github.com/rubysec/ruby-advisory-db/blob/master/gems/activestorage/CVE-2026-33174.yml