CVE-2026-126188: 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 3.7 Low · fixed in 8.0.5.2 : update rails when convenient.
Data as of 13 Nov 2026, 22:23 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 3.7 |
|---|
- Patch
- Available – fixed in 8.0.5.2
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:NExploitation 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 vulnerability is fixed. No other mitigation is indicated by the vendor advisory.
Description
A vulnerability in Rails Active Storage prior to 8.0.5.2 and from 8.1 until 8.1.4.1 allows attackers to cause FFmpeg to open local media files readable by the application process. This occurs because Active Storage's video and audio previewers and analyzers pass uploaded blob contents to FFmpeg without restricting the demuxer, enabling an attacker to craft uploads that trigger the hls demuxer and access local file:// segments. The issue is fixed in versions 8.0.5.2 and 8.1.4.1.
References
- ubuntu.com/security/CVE-2026-126188 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-126188 (opens in a new tab)
- github.com/rails/rails/security/advisories/GHSA-3f4q-8x5m-76v8 (opens in a new tab)
- github.com/rails/rails/commit/3b1f2627538dc597cd973530c08514a26c2b0282 (opens in a new tab)
- github.com/rails/rails/commit/69aff80d115bbb9d1e82fd6c6f2fd3ddeafb958b (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)