CVE-2026-66748

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.

CVSS 4.0

8.7CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS 3.1

8.8CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

1.1% chance of exploitation in the next 30 days; higher than 66% of CVEs (scores of 2026-10-25)

CWE

CWE-94

Published

2026-07-28

Modified

2026-10-24

Record from

the NVD, synced 2026-10-24

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

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