GHSA-r46p-8f7g-vvvg CVE-2026-33174
Rails Active Storage has a possible DoS vulnerability when in proxy mode via Range requests
- Severity
- 0.0 / 10
- High · CVSS 4.0
- Exploit chance (EPSS)
- 0.62%
- Chance of exploitation in the next 30 days. Higher than 49.80% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-789 Memory Allocation with Excessive Size Value
- Fix
8.1.2.1- Upgrade activestorage to this version or later
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
Affected versions
RubyGems
| Package | Vulnerable | Fixed in |
|---|---|---|
| activestorage | >= 8.1.0.beta1, < 8.1.2.1 |
8.1.2.1 |
| activestorage | >= 8.0.0.beta1, < 8.0.4.1 |
8.0.4.1 |
| activestorage | < 7.2.3.1 |
7.2.3.1 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
activestorage RubyGems → 8.1.2.1
- bundler
bundle update activestorage # Gemfile: gem "activestorage", ">= 8.1.2.1"
Severity breakdown
CVSS 4.0 0.0
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
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- None
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- None
- Availability (vulnerable system)
- High
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
- Exploit maturity
- Unreported
CVSS 3.1 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Weakness
CWE-789: Memory Allocation with Excessive Size Value
The product allocates memory based on an untrusted, large size value, but it does not ensure that the size is within expected limits, allowing arbitrary amounts of memory to be allocated.
How to prevent it
- Implementation, Architecture and Design: Perform adequate input validation against any value that influences the amount of memory that is allocated. Define an appropriate strategy for handling requests that exceed the limit, and consider supporting a configuration option so that the administrator can extend the amount of memory to be used if necessary.
- Operation: Run your program using system-provided resource limits for memory. This might still cause the program to crash or exit, but the impact to the rest of the system will be minimized.
References
Advisories
Packages
Other links
- github.com/rails/rails/security/advisories/GHSA-r46p-8f7g-vvvg
- github.com/rails/rails/commit/2cd933c366b777f873d4d590127da2f4a25e4ba5
- github.com/rails/rails/commit/42012eaaa88dfc7d0030161b2bc8074a7bbce92a
- github.com/rails/rails/commit/8159a9c3de3f27a2bcf2866b8bf9ceb9075e229b
- github.com/rails/rails/releases/tag/v7.2.3.1
- github.com/rails/rails/releases/tag/v8.0.4.1
- github.com/rails/rails/releases/tag/v8.1.2.1
- github.com/rubysec/ruby-advisory-db/blob/master/gems/activestorage/CVE-2026-331…
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-xr9x-r78c-5hrm Active Storage has possible arbitrary file read and remote code execution in Active Storage variant processing | Critical | Also affects activestorage |
| GHSA-p9fm-f462-ggrg Rails Active Storage has a possible DoS vulnerability in proxy mode via multi-range requests | Medium | Also affects activestorage |
| GHSA-73f9-jhhh-hr5m Rails Active Storage has possible glob injection in its DiskService | Critical | Also affects activestorage |
| GHSA-9xrj-h377-fr87 Rails Active Storage has possible Path Traversal in DiskService | Critical | Also affects activestorage |
| GHSA-qcfx-2mfw-w4cg Rails Active Storage has possible content type bypass via metadata in direct uploads | Medium | Also affects activestorage |
| GHSA-r4mg-4433-c7g3 Active Storage allowed transformation methods that were potentially unsafe | High | Also affects activestorage |
| GHSA-8h22-8cf7-hq6g Rails has possible Sensitive Session Information Leak in Active Storage | Medium | Also affects activestorage |
| GHSA-w749-p3v6-hccq Possible code injection vulnerability in Rails / Active Storage | Critical | Also affects activestorage |
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