CVE-2026-58409: File Upload RCE (CVSS 9.1)

Description

ChurchCRM is an open-source church management system. Prior to version 7.4.0, an authenticated administrator can achieve Remote Code Execution (RCE) on the server by installing a malicious plugin ZIP archive containing a PHP webshell. The application explicitly includes 'php' in its ALLOWED_EXTENSIONS list, while the dangerous extensions denylist (DENIED_EXTENSIONS) fails to block standard .php files. Because `php` is explicitly included in the allowed extension list for plugin archives, and extracted files are placed directly under the web root, any PHP file inside the ZIP becomes immediately executable via HTTP — without even needing to "enable" the plugin through the application UI. The /plugins/install-url API route (management.php) allows an administrator to source the malicious ZIP from any attacker-controlled HTTPS URL, validating it only against an attacker-supplied SHA-256 hash. This issue has been fixed in version 7.4.0.

Is your site exposed to CVE-2026-58409?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

9.1

CRITICAL

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

EPSS — Exploit Prediction

0.0046

Probability of exploitation

0.37%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-434 Unrestricted Upload

References

Other References

https://github.com/ChurchCRM/CRM/security/advisories/GHSA-37mf-vq43-5qp9 https://github.com/ChurchCRM/CRM/security/advisories/GHSA-37mf-vq43-5qp9

Frequently Asked Questions

What is CVE-2026-58409? +

ChurchCRM is an open-source church management system. Prior to version 7.4.0, an authenticated administrator can achieve Remote Code Execution (RCE) on the server by installing a malicious plugin ZIP archive containing a PHP webshell. The application explicitly includes 'php' in its ALLOWED_EXTENSIONS list, while the dangerous extensions denylist (DENIED_EXTENSIONS) fails to block standard .php files. Because `php` is explicitly included in the allowed extension list for plugin archives, and extracted files are placed directly under the web root, any PHP file inside the ZIP becomes immediately executable via HTTP — without even needing to "enable" the plugin through the application UI. The /plugins/install-url API route (management.php) allows an administrator to source the malicious ZIP from any attacker-controlled HTTPS URL, validating it only against an attacker-supplied SHA-256 hash. This issue has been fixed in version 7.4.0. It has a CVSS v3.1 base score of 9.1 (CRITICAL).

How severe is CVE-2026-58409? +

CVE-2026-58409 has a CVSS v3.1 score of 9.1 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0046, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-58409? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-3219

pip handles concatenated tar and ZIP files as ZIP files regardless of filename or whether a file is both a …

CVE-2024-43662

The <redacted>.exe or <redacted>.exe CGI binary can be used to upload arbitrary files to /tmp/upload/ or /tmp/ respectively as any …

CVE-2026-41517

Emlog is an open source website building system. Prior to version 2.6.11, insecure plugin upload functionality allows attackers to upload …

CVE-2026-5482

Responsive FileManager's allows an unauthenticated attacker to upload files of any type and extension without restriction using dialog.php endpoint, leading …

CVE-2026-34027

The Wertheim SafeController Software, AssemblyVersion 6.15.8328.28014, contains insufficient server-side file type validation in the /safe/contract/uploadcustomdocuments endpoint. The application validates uploaded …

CVE-2019-25714

Seeyon OA A8 contains an unauthenticated arbitrary file write vulnerability in the /seeyon/htmlofficeservlet endpoint that allows remote attackers to write …

CVE-2026-58409