CVE-2026-39544
Published: 08 April 2026
Summary
CVE-2026-39544 is a high-severity PHP Remote File Inclusion (CWE-98) vulnerability. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 34.9th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.
The strongest mitigations our analysis identified are NIST 800-53 RA-5 (Vulnerability Monitoring and Scanning) and SI-10 (Information Input Validation).
Deeper analysis
CVE-2026-39544 is an Improper Control of Filename for Include/Require Statement in PHP Program vulnerability, classified as PHP Remote File Inclusion but enabling PHP Local File Inclusion, affecting the LabtechCO WordPress theme developed by themeStek. The issue impacts all versions of LabtechCO up to and including 8.3, stemming from CWE-98. It carries a CVSS v3.1 base score of 7.5 (High), reflecting network accessibility with high attack complexity.
A low-privileged authenticated user (PR:L) can exploit this vulnerability remotely over the network (AV:N) without user interaction (UI:N), achieving high impacts on confidentiality, integrity, and availability (C:H/I:H/A:H) within the unchanged scope (S:U). Attackers could leverage the local file inclusion to read sensitive files, execute arbitrary code, or manipulate server resources on the targeted WordPress site.
The primary advisory is documented in the Patchstack database at https://patchstack.com/database/Wordpress/Theme/labtechco/vulnerability/wordpress-labtechco-theme-8-3-local-file-inclusion-vulnerability?_s_id=cve, which details the vulnerability in the LabtechCO theme version 8.3. Security practitioners should consult this resource for specific patch availability or workaround guidance, such as updating to a fixed version if released.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2026-20202
Vulnerability details
Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion') vulnerability in themeStek LabtechCO labtechco allows PHP Local File Inclusion.This issue affects LabtechCO: from n/a through <= 8.3.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
LFI vuln in public-facing WordPress theme directly enables T1190 (exploit public-facing app) for remote access and T1005 (data from local system) via sensitive file reads; arbitrary code execution possible but not tied to specific sub-technique.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly remediates the PHP local file inclusion vulnerability in LabtechCO theme versions up to 8.3 by requiring timely application of patches or removal of the affected component.
Prevents exploitation of improper filename control in PHP include/require by validating and sanitizing user-supplied inputs to block malicious local file inclusion.
Identifies the presence of CVE-2026-39544 through regular vulnerability scanning of deployed WordPress themes like LabtechCO for proactive remediation.