CVE-2026-126071: Rails · Active Storage makes it simple to upload and reference files in cloud services and attach
Affects railsSource GCVE Database
Not known to be exploited · CVSS 5.3 Medium · fixed in 8.0.5.2 : update rails when convenient.
Data as of 13 Nov 2026, 22:32 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 5.3 |
|---|
- Patch
- Available – fixed in 8.0.5.2
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 10 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 13 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 26.10railspkg:deb/ubuntu/rails?arch=source&distro=stonkingOther threats | Affected
| Fixed in– |
Ubuntu 26.04 LTSrailspkg:deb/ubuntu/rails?arch=source&distro=resoluteOther threats | Affected
| Fixed in– |
Ubuntu 24.04 LTSrailspkg:deb/ubuntu/rails?arch=source&distro=nobleOther threats | Affected
| Fixed in– |
Ubuntu Pro 22.04 LTSrailspkg:deb/ubuntu/rails?arch=source&distro=esm-apps/jammyOther threats | Affected
| Fixed in– |
Ubuntu Pro 20.04 LTSrailspkg:deb/ubuntu/rails?arch=source&distro=esm-apps/focalOther threats | Affected
| Fixed in– |
Ubuntu Pro 18.04 LTSrailspkg:deb/ubuntu/rails?arch=source&distro=esm-apps/bionicOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade Rails Active Storage to version 8.0.5.2 or later, or 8.1.4.1 or later, where this issue is fixed. No other mitigation is indicated or required.
Description
A denial-of-service vulnerability exists in Rails Active Storage versions from 8.0 up to 8.0.5.2 and 8.1 before 8.1.4.1. When serving files through proxy controllers, if an error occurs after the first chunk of a streamed file has been sent, the server thread handling the request can block indefinitely. This happens because the response buffer is never closed, potentially exhausting server threads upon repeated failed downloads. The issue affects applications using cloud storage services like Amazon S3 or Google Cloud Storage when files are deleted or errors occur mid-download. The vulnerability is fixed in versions 8.0.5.2 and 8.1.4.1.
References
- ubuntu.com/security/CVE-2026-126071 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-126071 (opens in a new tab)
- github.com/rails/rails/security/advisories/GHSA-4v2w-w6g6-f8f8 (opens in a new tab)
- github.com/rails/rails/commit/3c67a693fb21870ecb1222e3da59d5c491a62009 (opens in a new tab)
- github.com/rails/rails/commit/655b4442de136a3701334607f634d698bf9d5b82 (opens in a new tab)
- github.com/rails/rails/releases/tag/v8.0.5.2 (opens in a new tab)
- github.com/rails/rails/releases/tag/v8.1.4.1 (opens in a new tab)