CVE-2026-33174
Active Storage allows users to attach cloud and local files in Rails applications.
Does this matter?
Lower severity and a low EPSS score (0.62%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 4.0
- 6.6 MEDIUMCVSS: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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.62% probability · 49th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-789
- Affected
- rubyonrails/rails
- Source
- security-advisories@github.com
EPSS 0.6% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/rails/rails/commit/2cd933c366b777f873d4d590127da2f4a25e4ba5Patch
- https://github.com/rails/rails/commit/42012eaaa88dfc7d0030161b2bc8074a7bbce92aPatch
- https://github.com/rails/rails/commit/8159a9c3de3f27a2bcf2866b8bf9ceb9075e229bPatch
- https://github.com/rails/rails/releases/tag/v7.2.3.1Release Notes
- https://github.com/rails/rails/releases/tag/v8.0.4.1Release Notes
- https://github.com/rails/rails/releases/tag/v8.1.2.1Release Notes
- https://github.com/rails/rails/security/advisories/GHSA-r46p-8f7g-vvvgVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.