CyberSecBulletin
CVE-2026-122006NVD status: Awaiting Analysis

Active Storage: Initialization of a Resource with an Insecure Default

Published Updated By the CyberSecBulletin desk

CVE-2026-122006 is a critical-severity initialization of a resource with an insecure default vulnerability in Active Storage from Rubyonrails, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 8.0.5.2, 8.1.4.1 as the first without the flaw, so updating Active Storage to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.74% chance of exploitation within 30 days, higher than 55% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Active Storage to 8.0.5.2 or 8.1.4.1, whichever matches your release line, or a later version.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
RubyonrailsActive Storagebefore 8.0.5.2; 8.1 up to, but not including, 8.1.4.18.0.5.2, 8.1.4.1

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (mitre.org).

Official description

The activestorage gem before 8.1.4.1 for Ruby on Rails, when ImageMagick attachment processing occurs, can allow server read and write operations (e.g., reading secret_key_base) because the ImageMagick analyzer runs when a file is attached, and there is not an ImageMagick security policy to block unintended functionality.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Initialization of a Resource with an Insecure Default

The product initializes or sets a resource with a default that is intended to be changed by the product's installer, administrator, or maintainer, but the default is not secure.

More Initialization of a Resource with an Insecure Default vulnerabilities (CWE-1188)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Initialization of a Resource with an Insecure Default vulnerabilities

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