CVE-2026-22503
Published: 25 March 2026
Summary
CVE-2026-22503 is a high-severity PHP Remote File Inclusion (CWE-98) vulnerability. Its CVSS base score is 8.1 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 37.0th 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 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Directly remediates the PHP Local File Inclusion flaw in ThemeREX Nelson WordPress theme versions through 1.2.0 by applying vendor patches or upgrades.
Validates user-supplied inputs used in PHP include/require statements against whitelists or patterns to block arbitrary local file inclusion.
Deploys web application firewalls at system boundaries to inspect and block network requests containing path traversal payloads targeting this LFI vulnerability.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Public-facing LFI vulnerability in WordPress theme exploited remotely via T1190; enables reading sensitive local files (T1005) including those with credentials (T1552.001).
NVD Description
Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion') vulnerability in ThemeREX Nelson nelson allows PHP Local File Inclusion.This issue affects Nelson: from n/a through <= 1.2.0.
Deeper analysisAI
CVE-2026-22503 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, in the ThemeREX Nelson WordPress theme. This issue affects Nelson versions from n/a through 1.2.0. Published on 2026-03-25, it carries a CVSS v3.1 base score of 8.1 (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H) and maps to CWE-98.
Unauthenticated remote attackers can exploit this vulnerability over the network, though it requires high attack complexity and no user interaction. Successful exploitation grants high impacts across confidentiality, integrity, and availability, potentially allowing attackers to include and execute arbitrary local PHP files on the server.
The Patchstack advisory provides further details on this WordPress Nelson theme vulnerability, available at https://patchstack.com/database/Wordpress/Theme/nelson/vulnerability/wordpress-nelson-theme-1-2-0-local-file-inclusion-vulnerability?_s_id=cve.
Details
- CWE(s)