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RailsApplication · Rubyonrails

CVE-2026-33195

CRITICAL · 9.8 CVSS v3.1 Published 2026-03-24
Fix available
A fix is available. Upgrade to 7.2.3.1 / 8.0.4.1 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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, Active Storage's `DiskService#path_for` does not validate that the resolved filesystem path remains within the storage root directory. If a blob key containing path traversal sequences (e.g. `../`) is used, it could allow reading, writing, or deleting arbitrary files on the server. Blob keys are expected to be trusted strings, but some applications could be passing user input as keys and would be affected. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Active Storage's DiskService#path_for method in Rails fails to validate that resolved filesystem paths remain within the designated storage root directory. By supplying blob keys containing path traversal sequences (e.g., ../../), an attacker can read, write, or delete arbitrary files on the server. Applications that pass user-controlled input directly as blob keys are vulnerable.

MitigationUpgrade Rails to versions 8.1.2.1, 8.0.4.1, or 7.2.3.1. Additionally, audit the codebase to ensure blob keys are only derived from trusted/internal sources and never from user input.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
RailsApplication
Affected:< 7.2.3.1>= 8.0.0, < 8.0.4.1>= 8.1.0, < 8.1.2.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed Rails version
    Run `rails --version` in your application root, or check the Gemfile.lock for the rails gem version number
    Affected if The version is less than 7.2.3.1, OR between 8.0.0 and 8.0.4.1 inclusive, OR between 8.1.0 and 8.1.2.1 inclusive
  2. Verify Active Storage disk service is configured
    Check config/storage.yml for a service config with `disk:` as the service type, or inspect Active Storage configuration in your Rails environment
    Affected if Active Storage is configured to use the disk service for any storage bucket
  3. Identify blob key source and usage
    Search your codebase for where blob keys are created or assigned, particularly looking for cases where keys come from request parameters, user input, or external APIs
    Affected if Blob keys are derived from any untrusted or user-supplied input rather than generated internally by Rails
  4. Inspect path_for method for traversal protection
    Examine the Active Storage DiskService implementation in your Rails version by locating the path_for method in the gem, or check if the storage directory is validated to contain only resolved paths within the defined root
    Affected if The path_for method does not validate that the resolved path stays within the configured storage root directory

You are affected if your Rails version falls within the vulnerable ranges AND Active Storage disk service is in use AND blob keys could originate from untrusted input.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 7.2.3.1 / 8.0.4.1 / 8.1.2.1 or later
Fixed in 7.2.3.18.0.4.18.1.2.1
Vendor patch github.com →
Interim mitigation

Upgrade Rails to versions 8.1.2.1, 8.0.4.1, or 7.2.3.1. Additionally, audit the codebase to ensure blob keys are only derived from trusted/internal sources and never from user input.

Recommended fix High confidence

Rails 7.2.3.1, 8.0.4.1, or 8.1.2.1 (depending on your major version)

  1. Run `bundle update rails` to update to the latest patch version within your Rails series
  2. Alternatively, specify the exact fixed version in your Gemfile: `gem 'rails', '~> 7.2.3.1'` for 7.2.x, `gem 'rails', '~> 8.0.4.1'` for 8.0.x, or `gem 'rails', '~> 8.1.2.1'` for 8.1.x
  3. Run `bundle install` to install the updated gem
  4. Review your application for any code that passes user input directly as Active Storage blob keys, as blob keys should be trusted strings
  5. Deploy the updated version to production

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Rails Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing5.0 h
  • Review / QA3.0 h
17.0 hours of engineering $2,970
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-33195 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data