Skip to content

Unauthenticated users could execute project configuration sync operations that should be restricted trusted users

Moderate
angrybrad published GHSA-6mrr-q3pj-h53w Mar 24, 2026

Package

composer craftcms/cms (Composer)

Affected versions

>= 5.0.0-RC1, <= 5.9.13
>= 4.0.0-RC1, <= 4.17.7

Patched versions

5.9.14
4.17.8

Description

Summary

Guest users can access Config Sync updater index, obtain signed data, and execute state-changing Config Sync actions (regenerate-yaml, apply-yaml-changes) without authentication.

Details

ConfigSyncController extends BaseUpdaterController, and the base updater is anonymously accessible for control panel requests. index emits signed updater state (data), which can be reused by guests in subsequent requests.

Sensitive actions that are reachable via this method are actionApplyYamlChanges, actionRegenerateYaml, applyExternalChanges, and regenerateExternalConfig.

Reproduction steps

  1. Guest POST to:

    http POST /admin/actions/config-sync/index

  2. Extract data from returned JS state:

Craft.updater = ... setState({"data":"<signedData>", ...});
  1. Reuse data as a guest:
  POST /admin/actions/config-sync/regenerate-yaml
  data=<signedData>&<csrfParam>=<csrfToken>

or

  POST /admin/actions/config-sync/apply-yaml-changes
  data=<signedData>&<csrfParam>=<csrfToken>
  1. Observe completed response and state/file changes.

Impact

Unauthenticated users can execute project configuration sync operations that should be restricted to trusted admin/deployment contexts.

Depending on the pending YAML/config state, this can cause unauthorized config state transitions and a service integrity risk.

References

7f0ead833f7

Severity

Moderate

CVE ID

CVE-2026-33159

Weaknesses

Missing Authentication for Critical Function

The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources. Learn more on MITRE.

Missing Authorization

The product does not perform an authorization check when an actor attempts to access a resource or perform an action. Learn more on MITRE.

Credits