What’s Vulnerable › Vulnerabilities

CVE-2026-66748: Camaleon CMS 2.1.1 - 2.9.1 Authenticated RCE via select_eval Custom Field

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-28 · updated 2026-10-24
• Weakness: CWE-94

Description

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.

Affected products

• owen2345 camaleon-cms: from 2.1.1 through 2.9.1; 2.9.2

References

• https://enrik-m.github.io/posts/Camaleon-CMS-Vulnerabilties/
• https://github.com/owen2345/camaleon-cms/commit/158823668e2e5c3114a69b34cf1c96cb41533c5f
• https://github.com/owen2345/camaleon-cms/pull/1136
• https://github.com/owen2345/camaleon-cms/releases/tag/2.9.2
• https://github.com/theopaid/Camaleon-CMS---Authenticated-RCE-via-select_eval-Custom-Field
• https://tpaidakis.com/writeups/camaleon-cms-rce-select-eval/
• https://www.vulncheck.com/advisories/camaleon-cms-authenticated-rce-via-select-eval-custom-field
• https://github.com/theopaid/Camaleon-CMS---Authenticated-RCE-via-select_eval-Custom-Field

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