CVE-2026-33174
March 23, 2026
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.
Affected Packages
https://github.com/rails/rails.git (GITHUB):
Affected version(s) >=v0.5.0 <v7.2.3.1Fix Suggestion:
Update to version v7.2.3.1https://github.com/rails/rails.git (GITHUB):
Affected version(s) >=v8.0.0 <v8.0.4.1Fix Suggestion:
Update to version v8.0.4.1https://github.com/rails/rails.git (GITHUB):
Affected version(s) =v8.1.2 <v8.1.2.1Fix Suggestion:
Update to version v8.1.2.1activestorage (RUBY):
Affected version(s) >=8.0.0.beta1 <8.0.4.1Fix Suggestion:
Update to version 8.0.4.1activestorage (RUBY):
Affected version(s) >=0.1 <7.2.3.1Fix Suggestion:
Update to version 7.2.3.1activestorage (RUBY):
Affected version(s) >=8.1.0.beta1 <8.1.2.1Fix Suggestion:
Update to version 8.1.2.1Related Resources (9)
Do you need more information?
Contact UsCVSS v4
Base Score:
6.6
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
NONE
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
NONE
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
Exploit Maturity
UNREPORTED
CVSS v3
Base Score:
7.5
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Weakness Type (CWE)
Memory Allocation with Excessive Size Value
EPSS
Base Score:
0.02
