CVE-2026-126188

Active Storage: Possible local file disclosure in Active Storage video previews and analysis

Published Nov 10, 2026 CVSS 3.1 · 3.7 Low EPSS < 1% KEV · Not listed
Description
Active Storage makes it simple to upload and reference files in cloud services and attach those files to Active Record objects. Prior to 8.0.5.2 and from 8.1 until 8.1.4.1, Active Storage's ActiveStorage::Previewer::VideoPreviewer, ActiveStorage::Analyzer::VideoAnalyzer, and ActiveStorage::Analyzer::AudioAnalyzer pass uploaded blob contents to FFmpeg without restricting the demuxer. A direct upload can retain a client-declared video/* or audio/* content type for an HLS playlist. FFmpeg content probing selects the hls demuxer, which opens attacker-named file:// segments when the blob is previewed or analyzed. Applications that accept untrusted uploads and generate video previews or analyze video or audio attachments can disclose a local media file readable by the application process when the attacker knows its path. This issue is fixed in versions 8.0.5.2 and 8.1.4.1.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-3f4q-8x5m-76v8 Active Storage: Possible local file disclosure in video previews and analysis
History
Type Values Removed Values Added
First Time appeared Rails
Rails rails
Vendors & Products Rails
Rails rails
Type Values Removed Values Added
Description Active Storage makes it simple to upload and reference files in cloud services and attach those files to Active Record objects. Prior to 8.0.5.2 and from 8.1 until 8.1.4.1, Active Storage's ActiveStorage::Previewer::VideoPreviewer, ActiveStorage::Analyzer::VideoAnalyzer, and ActiveStorage::Analyzer::AudioAnalyzer pass uploaded blob contents to FFmpeg without restricting the demuxer. A direct upload can retain a client-declared video/* or audio/* content type for an HLS playlist. FFmpeg content probing selects the hls demuxer, which opens attacker-named file:// segments when the blob is previewed or analyzed. Applications that accept untrusted uploads and generate video previews or analyze video or audio attachments can disclose a local media file readable by the application process when the attacker knows its path. This issue is fixed in versions 8.0.5.2 and 8.1.4.1.
Title Active Storage: Possible local file disclosure in Active Storage video previews and analysis
Weaknesses CWE-200
References
Metrics cvssV3_1

{'score': 3.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Nov 12, 2026, 7:14 PM
Reserved
Nov 10, 2026, 8:07 PM
Status
Awaiting Analysis
Published
Nov 11, 2026, 12:18 AM
Modified
Nov 12, 2026, 10:09 PM