CVE-2026-39387 BoidCMS: Local File Inclusion (LFI) leads to Remote Code Execution (RCE) via tpl parameter
An authenticated administrator can exploit a path traversal vulnerability in the tpl parameter to include arbitrary files, leading to remote code execution.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-39387?
CVE-2026-39387 is a high-severity path traversal vulnerability in BoidCMS, published on 14 Apr 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official 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.
Weakness: CWE-98
Which versions are affected by CVE-2026-39387?
It affects 1 product.
Products include Boidcms Boidcms.
How do I fix CVE-2026-39387?
No fix has been published for CVE-2026-39387 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-39387 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-39387 exists.
Public exploit code: 1 proofs of concept on GitHub.
Other vulnerabilities in BoidCMS
Sources
Also known as GHSA-45xp-xw54-6cv6.