CVE-2026-126186: 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 8.8 High · fixed in 8.1.4.1 : patch rails soon.
Data as of 13 Nov 2026, 22:23 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 8.8 |
|---|
- Patch
- Available – fixed in 8.1.4.1
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/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 8.1.4.1 or 8.0.5.2 or later where this vulnerability is fixed. If upgrading is not immediately possible, restrict uploads from untrusted users or disable media analysis features that invoke ffprobe, ffmpeg, or ImageMagick on untrusted files. Verify the FFmpeg build configuration to ensure AviSynth support is not enabled if not required. Monitor vendor advisories for further guidance.
Description
A vulnerability in Rails Active Storage prior to versions 8.1.4.1 and 8.0.5.2 allows attackers who can upload files to influence how external tools like ffprobe, ffmpeg, and ImageMagick decode those files. By controlling the filename extension and content type, an attacker may cause these tools to process malicious inputs, potentially leading to information disclosure or remote code execution, especially if FFmpeg is built with AviSynth support. The issue is fixed in versions 8.1.4.1 and 8.0.5.2.
References
- ubuntu.com/security/CVE-2026-126186 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2026-126186 (opens in a new tab)
- github.com/rails/rails/security/advisories/GHSA-v924-7rp8-4mxh (opens in a new tab)
- github.com/rails/rails/commit/72136ff39153bc8d63ecbc899993848eb3d6573e (opens in a new tab)
- github.com/rails/rails/commit/8106938fb0a595f11006dd1497cd409e27d7d636 (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)