---
id: CVE-2026-66748
title: >-
  Camaleon CMS versions 2.1.1 through 2.9.1 contains an authenticated remote
  code execution vulnerability that allows users with custom_fields manage
  permission to execute arbitrary Ruby code by supplying a malicious expression
  through the…
summary: >-
  Camaleon CMS versions 2.1.1 through 2.9.1 contains an authenticated remote
  code execution vulnerability that allows users with custom_fields manage
  permission to execute arbitrary Ruby code by supplying a malicious expression
  through the…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-94
published: '2026-07-28'
updated: '2026-07-31'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-66748'
references:
  - url: 'https://enrik-m.github.io/posts/Camaleon-CMS-Vulnerabilties/'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/owen2345/camaleon-cms/commit/158823668e2e5c3114a69b34cf1c96cb41533c5f
    label: disclosure@vulncheck.com
  - url: 'https://github.com/owen2345/camaleon-cms/pull/1136'
    label: disclosure@vulncheck.com
  - url: 'https://github.com/owen2345/camaleon-cms/releases/tag/2.9.2'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/theopaid/Camaleon-CMS---Authenticated-RCE-via-select_eval-Custom-Field
    label: disclosure@vulncheck.com
  - url: 'https://tpaidakis.com/writeups/camaleon-cms-rce-select-eval/'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/camaleon-cms-authenticated-rce-via-select-eval-custom-field
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/theopaid/Camaleon-CMS---Authenticated-RCE-via-select_eval-Custom-Field
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - exploit-available
epss: 0.00834
epssPercentile: 0.56172
ingestedAt: '2026-08-01T21:14:39.393Z'
exploits:
  github: 1
  githubRepos:
    - >-
      https://github.com/theopaid/CVE-2026-66748-Camaleon-CMS---Authenticated-RCE-via-select_eval-Custom-Field
  checkedAt: '2026-09-24T07:53:12.751Z'
exploitAvailable: true
---

## Overview

Camaleon CMS versions 2.1.1 through 2.9.1 contains an authenticated remote code execution vulnerability that allows users with custom_fields manage permission to execute arbitrary Ruby code by supplying a malicious expression through the select_eval custom field type. Attackers can store an attacker-controlled Ruby expression in the field options command parameter, which is evaluated via instance_eval within an ERB view whenever a post edit page is rendered, achieving server-side code execution with web server process privileges.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.