CVE-2026-33174
Rails Active Storage has a possible DoS vulnerability when in proxy mode via Range requests
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Rails Active Storage has a possible DoS vulnerability when in proxy mode via Range requests
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.
- Record
CVE-2026-33174- CVSS 4.0
- 6.6 Medium
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 - Weakness
- CWE-789
- Updated
- 2026-11-02
EUVDEUVD-2026-14628
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.
- Record
EUVD-2026-14628- CVSS 4.0
- 6.6 Medium
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 - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-r46p-8f7g-vvvg
Rails Active Storage has a possible DoS vulnerability when in proxy mode via Range requests
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
- Record
GHSA-r46p-8f7g-vvvg- CVSS 4.0
- 6.6 Medium
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 - Weakness
- CWE-789
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-33174- CVSS 4.0
- 6.6 Medium
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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-789
- Updated
- 2026-11-02
OSV
Rails Active Storage has a possible DoS vulnerability when in proxy mode via Range requests
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.
- Record
CVE-2026-33174- CVSS 4.0
- 6.6 Medium
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 - Weakness
- CWE-789
- Updated
- 2026-11-02
OSVDEBIAN-CVE-2026-33174
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.
- Record
DEBIAN-CVE-2026-33174- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVGHSA-r46p-8f7g-vvvg
Rails Active Storage has a possible DoS vulnerability when in proxy mode via Range requests
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
- Record
GHSA-r46p-8f7g-vvvg- CVSS 4.0
- 6.6 Medium
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 - Weakness
- CWE-789
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2026-33174
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.
- Record
UBUNTU-CVE-2026-33174- CVSS 4.0
- 6.6 Medium
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 - CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
activestorageRubyGems |
8.1.0.beta1 up to 8.1.2.1 | 8.1.2.1 |
activestorageRubyGems |
8.0.0.beta1 up to 8.0.4.1 | 8.0.4.1 |
activestorageRubyGems |
before 7.2.3.1 | 7.2.3.1 |
railsDebian:13 |
before 2:7.2.2.2+dfsg-2~deb13u2, plus listed versions 2:7.2.2.1+dfsg-72:7.2.2.2+dfsg-12:7.2.2.2+dfsg-2~deb13u1 |
2:7.2.2.2+dfsg-2~deb13u2 |
railsDebian:14 |
before 2:7.2.3.1+dfsg-1, plus listed versions 2:7.2.2.1+dfsg-72:7.2.2.2+dfsg-12:7.2.2.2+dfsg-22:7.2.2.2+dfsg-2~deb13u12:7.2.2.2+dfsg-2~deb13u22:7.2.3+dfsg-12:7.2.3+dfsg-22:7.2.3+dfsg-3 |
2:7.2.3.1+dfsg-1 |
activestorageRubyGems |
8.1.0.beta1 up to 8.1.2.1, plus listed versions 8.1.08.1.0.rc18.1.18.1.2 |
8.1.2.1 |
activestorageRubyGems |
8.0.0.beta1 up to 8.0.4.1, plus listed versions 8.0.08.0.0.18.0.0.rc18.0.0.rc28.0.1 Show 4 moreShow less8.0.28.0.2.18.0.38.0.4 |
8.0.4.1 |
activestorageRubyGems |
before 7.2.3.1, plus listed versions 0.15.2.05.2.0.beta15.2.0.beta25.2.0.rc1 Show 45 moreShow less5.2.0.rc25.2.15.2.1.15.2.1.rc15.2.25.2.2.15.2.2.rc15.2.35.2.3.rc15.2.45.2.4.15.2.4.25.2.4.35.2.4.45.2.4.55.2.4.65.2.4.rc15.2.55.2.65.2.6.15.2.6.25.2.6.35.2.75.2.7.15.2.85.2.8.16.0.06.0.0.beta16.0.0.beta26.0.0.beta36.0.0.rc16.0.0.rc26.0.16.0.1.rc16.0.26.0.2.16.0.2.26.0.2.rc16.0.2.rc26.0.36.0.3.16.0.3.26.0.3.36.0.3.46.0.3.5 |
7.2.3.1 |
railsUbuntu:Pro:16.04:LTS |
All versions, plus listed versions 2:4.1.10-12:4.2.5-12:4.2.5.1-12:4.2.5.2-22:4.2.6-12:4.2.6-1ubuntu0.1~esm12:4.2.6-1ubuntu0.1~esm2 |
None known |
railsUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 2:4.2.9-22:4.2.9-42:4.2.10-0ubuntu42:4.2.10-0ubuntu4+esm12:4.2.10-0ubuntu4+esm2 |
None known |
Show 6 moreShow less
| Package | Affected | Fixed |
|---|---|---|
railsUbuntu:Pro:20.04:LTS |
All versions, plus listed versions 2:5.2.2.1+dfsg-1ubuntu12:5.2.3+dfsg-32:5.2.3+dfsg-3ubuntu0.1~esm1 |
None known |
railsUbuntu:Pro:22.04:LTS |
All versions, plus listed versions 2:6.0.3.7+dfsg-22:6.1.4.1+dfsg-8ubuntu22:6.1.4.1+dfsg-8ubuntu2+esm1 |
None known |
railsUbuntu:24.04:LTS |
All versions, plus listed versions 2:6.1.7.3+dfsg-2build12:6.1.7.3+dfsg-3 |
None known |
railsUbuntu:25.10 |
All versions, plus listed versions 2:6.1.7.3+dfsg-72:7.2.2.1+dfsg-7 |
None known |
railsUbuntu:26.10 |
All versions, plus listed versions 2:7.2.3+dfsg-22:7.2.3.2+dfsg-2 |
None known |
railsUbuntu:26.04:LTS |
All versions, plus listed versions 2:7.2.2.1+dfsg-72:7.2.2.2+dfsg-22:7.2.3+dfsg-2 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-33174 is a medium vulnerability (CVSS 6.6) in Rubyonrails Rails, published March 23, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.62%, the 49th percentile. Fixed in activestorage 8.1.2.1.
References
github.com/rails/rails/security/advisories/GHSA-r46p-8f7g-vvvg
Show 9 moreShow less
nvd.nist.gov/vuln/detail/CVE-2026-33174
security-tracker.debian.org/tracker/CVE-2026-33174
ubuntu.com/security/CVE-2026-33174
cve.org/CVERecord?id=CVE-2026-33174
Left out here: 111 versions. The JSON record has them.