CVE-2026-33174
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, when serving files through Active Storage's proxy delivery mode, the proxy 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. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
SUSE Affected 1 release
| Version | Status | Fixed in |
|---|---|---|
| — | Affected | — |
Debian Mixed 5 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Affected | — |
| sid | Fixed | 2:7.2.3.1+dfsg-1 |
| forky | Fixed | 2:7.2.3.1+dfsg-1 |
| bullseye | Affected | — |
| bookworm | Affected | — |
Package impact
| Ecosystem | Package | Vulnerable | Fixed |
|---|---|---|---|
| RubyGems | activestorage | <~> 7.2.3, >= 7.2.3.1 | ~> 7.2.3, >= 7.2.3.1 |
| RubyGems | activestorage | >=8.1.0.beta1,<8.1.2.1 | 8.1.2.1 |
| RubyGems | activestorage | >=8.0.0.beta1,<8.0.4.1 | 8.0.4.1 |
| RubyGems | activestorage | <7.2.3.1 | 7.2.3.1 |
| RUBYGEMS | activestorage | < 7.2.3.1 | 7.2.3.1 |
| RUBYGEMS | activestorage | >= 8.0.0.beta1, < 8.0.4.1 | 8.0.4.1 |
| RUBYGEMS | activestorage | >= 8.1.0.beta1, < 8.1.2.1 | 8.1.2.1 |
References
- https://github.com/rails/rails/security/advisories/GHSA-r46p-8f7g-vvvg
- https://www.suse.com/security/cve/CVE-2026-33174.html
- https://nvd.nist.gov/vuln/detail/CVE-2026-33174
- https://github.com/rails/rails/commit/2cd933c366b777f873d4d590127da2f4a25e4ba5
- https://github.com/rails/rails/commit/42012eaaa88dfc7d0030161b2bc8074a7bbce92a
- https://github.com/rails/rails/commit/8159a9c3de3f27a2bcf2866b8bf9ceb9075e229b
- https://github.com/rails/rails
- https://github.com/rails/rails/releases/tag/v7.2.3.1
- https://github.com/rails/rails/releases/tag/v8.0.4.1
- https://github.com/rails/rails/releases/tag/v8.1.2.1
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/activestorage/CVE-2026-33174.yml
- https://security-tracker.debian.org/tracker/CVE-2026-33174
- https://github.com/advisories/GHSA-r46p-8f7g-vvvg
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.