CVE-2026-23885: AlchemyCMS has Authenticated Remote Code Execution (RCE) via eval injection in ResourcesHelper

Severity: critical (CVSS 9.9 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-01-19 · updated 2026-06-17
Weakness: CWE-95

Description

Alchemy is an open source content management system engine written in Ruby on Rails. Prior to versions 7.4.12 and 8.0.3, the application uses the Ruby `eval()` function to dynamically execute a string provided by the `resource_handler.engine_name` attribute in `Alchemy::ResourcesHelper#resource_url_proxy`. The vulnerability exists in `app/helpers/alchemy/resources_helper.rb` at line 28. The code explicitly bypasses security linting with `# rubocop:disable Security/Eval`, indicating that the use of a dangerous function was known but not properly mitigated. Since `engine_name` is sourced from module definitions that can be influenced by administrative configurations, it allows an authenticated attacker to escape the Ruby sandbox and execute arbitrary system commands on the host OS. Versions 7.4.12 and 8.0.3 fix the issue by replacing `eval()` with `send()`.

Affected products

AlchemyCMS alchemy_cms: before 7.4.12; from 8.0.0 before 8.0.3 — fixed in 7.4.12, 8.0.3

How to fix

Upgrade to a fixed version: AlchemyCMS alchemy_cms 7.4.12, 8.0.3. Check the vendor advisory for mitigations.

References

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