CVE-2026-39387: BoidCMS is an open-source, PHP-based flat-file CMS for building simple websites and blogs, using JSON as its database. Versions prior to 2.1.3 are vul...

Description

BoidCMS is an open-source, PHP-based flat-file CMS for building simple websites and blogs, using JSON as its database. Versions prior to 2.1.3 are vulnerable to a critical Local File Inclusion (LFI) attack via the tpl parameter, which can lead to Remote Code Execution (RCE).The application fails to sanitize the tpl (template) parameter during page creation and updates. This parameter is passed directly to a require_once() statement without path validation. An authenticated administrator can exploit this by injecting path traversal sequences (../) into the tpl value to escape the intended theme directory and include arbitrary files — specifically, files from the server's media/ directory. When combined with the file upload functionality, this becomes a full RCE chain: an attacker can first upload a file with embedded PHP code (e.g., disguised as image data), then use the path traversal vulnerability to include that file via require_once(), executing the embedded code with web server privileges. This issue has been fixed in version 2.1.3.

Metrics

CVSS 3.1

7.2/10

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

EPSS Probability

0.73%

49.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-98

Affected Software

Vendor	Product	Versions
Boidcms	Boidcms	< 2.1.3

References

https://github.com/BoidCMS/BoidCMS/releases/tag/v2.1.3Product, Release Notes
https://github.com/BoidCMS/BoidCMS/security/advisories/GHSA-45xp-xw54-6cv6Exploit, Mitigation, Vendor Advisory
https://github.com/BoidCMS/BoidCMS/security/advisories/GHSA-45xp-xw54-6cv6Exploit, Mitigation, Vendor Advisory

Timeline

Published: Apr 14, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-39387?

BoidCMS is an open-source, PHP-based flat-file CMS for building simple websites and blogs, using JSON as its database. Versions prior to 2.1.3 are vulnerable to a critical Local File Inclusion (LFI) attack via the tpl parameter, which can lead to Remote Code Execution (RCE).The application fails to sanitize the tpl (template) parameter during page creation and updates. This parameter is passed directly to a require_once() statement without path validation. An authenticated administrator can exploit this by injecting path traversal sequences (../) into the tpl value to escape the intended theme directory and include arbitrary files — specifically, files from the server's media/ directory. When combined with the file upload functionality, this becomes a full RCE chain: an attacker can first upload a file with embedded PHP code (e.g., disguised as image data), then use the path traversal vulnerability to include that file via require_once(), executing the embedded code with web server privileges. This issue has been fixed in version 2.1.3.

How severe is CVE-2026-39387?

CVE-2026-39387 has a CVSS score of 7.2/10 (HIGH severity). The EPSS model estimates a 0.73% probability of exploitation in the next 30 days.

How do I fix CVE-2026-39387?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.