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NVD / CVE Program· CNA GitHub_M

CVE-2026-66066: Action Pack: Possible arbitrary file read and remote code execution in Active Storage variant processing

Noroxi assessment

Priority: This week (action score 60/100)

  • A ready-made attack module is public (Metasploit); exploiting it takes no special expertise.
  • A ready-made attack tool exists and the flaw can be exploited over the network without an account, so priority is at least “This week”.
  • Probability of exploitation in the next 30 days: 26.5% (FIRST EPSS); higher than 98% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • Fixed version: rails (Debian:12) 2:6.1.7.10+dfsg-1~deb12u3; rails (Debian:13) 2:7.2.2.2+dfsg-2~deb13u2; rails (Debian:14) 2:7.2.3.2+dfsg-1.

Don’t wait for the next maintenance window. Upgrade to rails (Debian:12) 2:6.1.7.10+dfsg-1~deb12u3; rails (Debian:13) 2:7.2.2.2+dfsg-2~deb13u2; rails (Debian:14) 2:7.2.3.2+dfsg-1 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

Action Pack is a framework for handling and responding to web requests. In versions prior to 7.2.3.2, 8.0.5.1 and 8.1.3.1, Active Storage does not disable libvips operations marked unsafe for untrusted content, allowing a crafted upload to invoke such an operation. Consuming applications are affected when configured to use libvips and accept image uploads from untrusted users. An unauthenticated attacker may exploit this behavior to read arbitrary files accessible to the Rails process, including environment variables and application secrets. Exposure of credentials such as secret_key_base or external-service tokens may enable remote code execution or lateral movement. This issue has been fixed in versions 7.2.3.2, 8.0.5.1 and 8.1.3.1.

CriticalCVSS 9.5 · v4.0—Weaponized Fix available
Published
Jul 30, 2026
Updated
Sep 10, 2026
EPSS
26.5% · 98th percentile

Report tools

JSON

Action score

60

This week

Don’t wait for the next maintenance window.

CVSS
38 / 40 · 9.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
8 / 30 · 26.5%
Ready-made attack tool
14 / 60 · floor: at least 60

CISA SSVC decision

Exploitation
proof of concept
Automatable
yes
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
9.5
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • Weaponized exploit exists
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-66066

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • rails rails

    • < 7.2.3.2, >= 8.0.0.beta1, < 8.0.5.1, >= 8.1.0.beta1, < 8.1.3.1affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12railsbefore 2:6.1.7.10+dfsg-1~deb12u32:6.1.7.10+dfsg-1~deb12u3
Debian:13railsbefore 2:7.2.2.2+dfsg-2~deb13u22:7.2.2.2+dfsg-2~deb13u2
Debian:14railsbefore 2:7.2.3.2+dfsg-12:7.2.3.2+dfsg-1
openSUSE:Leap 16.0hawk2before 2.7.2+git.1788518533.7d4dadd6-160000.1.12.7.2+git.1788518533.7d4dadd6-160000.1.1
openSUSE:Tumbleweedhawk2before 2.7.2+git.1792148770.648dcddb-1.12.7.2+git.1792148770.648dcddb-1.1
RubyGemsactivestoragefrom 8.0.0.beta1 · before 8.0.5.18.0.5.1
RubyGemsactivestoragefrom 8.1.0.beta1 · before 8.1.3.18.1.3.1
RubyGemsactivestoragebefore 7.2.3.27.2.3.2
SUSE:Linux Enterprise High Availability Extension 16.0hawk2before 2.7.2+git.1788518533.7d4dadd6-160000.1.12.7.2+git.1788518533.7d4dadd6-160000.1.1

Same product

rails: all records

Other highest-scoring records for the same primary product.

  • CVE-2024-47889Action Mailer has possible ReDoS vulnerability in block_format
    26Monitor
  • CVE-2024-47888Action Text has possible ReDoS vulnerability in plain_text_for_blockquote_node
    26Monitor
  • CVE-2024-47887Action Controller has possible ReDoS vulnerability in HTTP Token authentication
    26Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2024-41128Oct 16, 2024 · Action Dispatch has possible ReDoS vulnerability in query parameter filtering
    26Monitor
  • ← EarlierCVE-2024-54133Dec 10, 2024 · Possible Content Security Policy bypass in Action Dispatch
    9Monitor
  • ← EarlierCVE-2025-55193Aug 13, 2025 · Active Record logging vulnerable to ANSI escape injection
    10Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
debian:rails2:6.1.7.10+dfsg-1~deb12u3 · Debian:12Package registry (OSV)
debian:rails2:7.2.2.2+dfsg-2~deb13u2 · Debian:13Package registry (OSV)
debian:rails2:7.2.3.2+dfsg-1 · Debian:14Package registry (OSV)
opensuse:hawk22.7.2+git.1792148770.648dcddb-1.1 · openSUSE:TumbleweedPackage registry (OSV)
RubyGems:activestorage7.2.3.2Package registry (OSV)
RubyGems:activestorage8.0.5.1Package registry (OSV)
RubyGems:activestorage8.1.3.1Package registry (OSV)
suse:hawk22.7.2+git.1788518533.7d4dadd6-160000.1.1 · SUSE:Linux Enterprise High Availability Extension 16.0Package registry (OSV)

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Evidence

  • Metasploit module ×1
  • Proof-of-concept repository on GitHub ×7

Noroxi does not host or link to exploit code. Metasploit module names and Nuclei template ids are shown (names, not code); Exploit-DB entries and PoC repositories are given as counts only.

Public exploit evidence
SourceKindDate
Metasploit moduleexploit/multi/http/rails_activestorage_vips_rceRuby on Rails Active Storage Vips Arbitrary File Read and Remote Code Executionexploit2026-07-29
Proof-of-concept repository on GitHubstars:12026-07-29
Proof-of-concept repository on GitHubstars:232026-07-29
Proof-of-concept repository on GitHubstars:302026-07-30
Proof-of-concept repository on GitHubstars:52026-07-31
Proof-of-concept repository on GitHubstars:42026-08-03
Proof-of-concept repository on GitHubstars:12026-08-04
Proof-of-concept repository on GitHubstars:02026-09-10

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. First PoC-2 d
  2. Metasploit-2 d
  3. Published
  4. TodayOct 29, 2026+90 d
EPSS, last 120 days-1% in 7 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

The product’s vendor appears in a public program. Matched by name; verify the scope text in the program.

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
X

Weakness class (CWE)

CWE-1188 · Initialization of a Resource with an Insecure Default

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (12 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records