CI4MS Vulnerable to Post-Installation Re-entry via Cache-Dependent Install Guard Bypass

Exploitation

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

CVSS

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

EPSS

• CVE-2026-39393: 0.42% estimated exploitation activity in the next 30 days; percentile 36.46 (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 The install route guard in ci4ms relies solely on a volatile cache check (cache('settings')) combined with .env file existence to block post-installation access to the setup wizard. When the database is temporarily unreachable during a cache miss (TTL expiry or admin-triggered cache clear), the guard fails open, allowing an unauthenticated attacker to overwrite the .env file with attacker-controlled database credentials, achieving full application takeover. Details The InstallFilter::before() method at modules/Install/Filters/InstallFilter.php:13 implements the install guard: This requires both conditions — .env existence AND non-empty cache — to block access. The cache population happens in app/Config/Filters.php:128-151 during the Filters constructor, which runs before route-specific filters: When the database is unreachable (connection failure, timeout, maintenance), the \Throwable catch at line 148-150 silently swallows the exception. The cache remains empty, and…

Published by the source

8 Apr 2026, 19:15 UTC

Last modified by the source

8 Apr 2026, 19:15 UTC

Source last checked

26 Oct 2026, 14:39 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-8rh5-4mvx-xj7j

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# Patch Next advisory brief: CVE-2026-39393

Advisory: CI4MS Vulnerable to Post-Installation Re-entry via Cache-Dependent Install Guard Bypass
IDs: CVE-2026-39393, GHSA-8rh5-4mvx-xj7j
Record: https://patchnext.com/advisories/cve-2026-39393 (revision 1, source checked 26 Oct 2026, 14:39 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: ci4-cms-erp/ci4ms 0.31.4.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist ci4-cms-erp/ci4ms: affected <= 0.31.3.0; fixed in 0.31.4.0

## Suggested inspection (read-only)
- Packagist ci4-cms-erp/ci4ms: 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 ci4-cms-erp/ci4ms.
- 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-8rh5-4mvx-xj7j (GitHub-reviewed advisory GHSA-8rh5-4mvx-xj7j lists affected ranges: Packagist ci4-cms-erp/ci4ms >=0 <=0.31.3.0)

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