AlchemyCMS: Authenticated Remote Code Execution (RCE) via eval injection in ResourcesHelper

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

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

EPSS

• CVE-2026-23885: 0.47% estimated exploitation activity in the next 30 days; percentile 40.89 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary A vulnerability was discovered during a manual security audit of the AlchemyCMS source code. The application uses the Ruby eval() function to dynamically execute a string provided by the resourcehandler.enginename attribute in Alchemy::ResourcesHelper#resourceurlproxy. Details The vulnerability exists in app/helpers/alchemy/resourceshelper.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 enginename 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. But, for this attack to be possible local file access to the alchemy project or the source on a remote server is necessary in order to manipulate the module config file, though. PoC (Proof of Concept) The following standalone Ruby script…

Published by the source

21 Jan 2026, 01:04 UTC

Last modified by the source

2 Feb 2026, 14:45 UTC

Source last checked

26 Oct 2026, 15:51 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-2762-657x-v979

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# Patch Next advisory brief: CVE-2026-23885

Advisory: AlchemyCMS: Authenticated Remote Code Execution (RCE) via eval injection in ResourcesHelper
IDs: CVE-2026-23885, GHSA-2762-657x-v979
Record: https://patchnext.com/advisories/cve-2026-23885 (revision 1, source checked 26 Oct 2026, 15:51 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.4)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: alchemy_cms 8.0.3, 7.4.12. A vendor fix does not mean a deployment is fixed.

## Affected components
- RubyGems alchemy_cms: affected < 7.4.12; >= 8.0.0.a, < 8.0.3; fixed in 8.0.3, 7.4.12

## Suggested inspection (read-only)
- RubyGems alchemy_cms: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on alchemy_cms.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-2762-657x-v979 (GitHub-reviewed advisory GHSA-2762-657x-v979 lists affected ranges: RubyGems alchemy_cms >=0 =8.0.0.a <8.0.3)

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