CVE-2026-39393 json
Post-Installation Re-entry via Cache-Dependent Install Guard Bypass in ci4ms
published 2026-04-08 7 mo ago modified 2026-07-24 3 mo ago also EUVD-2026-20487 , GHSA-8rh5-4mvx-xj7j
- cvss
- 8.1
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 37%
- public exploits
- 0
- none known
Summary
CI4MS is a CodeIgniter 4-based CMS skeleton that delivers a production-ready, modular architecture with RBAC authorization and theme support. Prior to 0.31.4.0, 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. This vulnerability is fixed in 0.31.4.0.
Patch / fix
- packagist ci4-cms-erp/ci4ms 0.31.4.0
- ci4-cms-erp ci4ms 0.31.4.0
CISA SSVC
- Exploitation
- Proof of concept is public
- Automatable
- no
- Technical impact
- total
- Assessed
- 6 mo ago
Exploit prediction
0.43% chance of exploitation in the next 30 days, higher than 37% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- github.com https://github.com/ci4-cms-erp/ci4ms/security/advisories/GHSA-8rh5-4mvx-xj7j referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| GitHub | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 3.1 | 8.1 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| packagist | ci4-cms-erp/ci4ms | <0.31.4.0 |
0.31.4.0 |
Affected products
- ci4-cms-erp ci4ms
Classification
- Weakness
-
- CWE-306 Missing Authentication for Critical Functionality
References
-
github.com
/ci4-cms-erp/ci4ms/security/advisories/GHSA-8rh5-4mvx-xj7j
web, exploit, vendor-advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-39393
advisory
-
github.com
/ci4-cms-erp/ci4ms
package
-
github.com
/ci4-cms-erp/ci4ms/releases/tag/0.31.4.0
web
Sources
- CVE List CVE-2026-39393
- GitHub Advisory GHSA-8rh5-4mvx-xj7j
- NVD CVE-2026-39393
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.