CVE-2026-33174
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
Package Versions Affected
Automatically patch vulnerabilities without upgrading
CVSS Version



Related Resources
References
https://github.com/rails/rails/security/advisories/GHSA-r46p-8f7g-vvvg, 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
