Cyber Resilience

CVE-2026-28055

High

Published: 05 March 2026

Published
05 March 2026
Modified
22 April 2026
KEV Added
—
Patch
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CVSS Score v3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0040 32.0th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-28055 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 32.0th 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).

Deeper analysis

CVE-2026-28055 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 M.Williamson WordPress theme (also referred to as williamson). This issue affects all versions of M.Williamson up to and including 1.2.11. The vulnerability was published on 2026-03-05 and 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), mapped to CWE-98.

An unauthenticated attacker with network access can exploit this vulnerability remotely. Exploitation requires high attack complexity but no privileges or user interaction, allowing the attacker to achieve high impacts on confidentiality, integrity, and availability, such as local file disclosure or potential code execution via included files.

The Patchstack advisory provides details on mitigation for this WordPress theme vulnerability: https://patchstack.com/database/Wordpress/Theme/williamson/vulnerability/wordpress-m-williamson-theme-1-2-11-local-file-inclusion-vulnerability?_s_id=cve.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability details

Improper Control of Filename for Include/Require Statement in PHP Program ('PHP Remote File Inclusion') vulnerability in ThemeREX M.Williamson williamson allows PHP Local File Inclusion.This issue affects M.Williamson: from n/a through <= 1.2.11.

CWE(s)
CWE-98

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1005 Data from Local System Collection
Adversaries may search local system sources, such as file systems, configuration files, local databases, virtual machine files, or process memory, to find files of interest and sensitive data prior to Exfiltration.
attack.mitre.org →
Why these techniques?

LFI vulnerability in public-facing WordPress theme enables T1190 (exploit public-facing application) for initial access and T1005 (data from local system) via arbitrary local file inclusion, with high C/I/A impacts indicating direct facilitation.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2025-60057Shared CWE-98
CVE-2025-58940Shared CWE-98
CVE-2026-22476Shared CWE-98
CVE-2025-67980Shared CWE-98
CVE-2025-69034Shared CWE-98
CVE-2025-58225Shared CWE-98
CVE-2026-22427Shared CWE-98
CVE-2025-69402Shared CWE-98
CVE-2025-64205Shared CWE-98
CVE-2026-28013Shared CWE-98

Affected Assets

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SI-2 Flaw Remediation good match
prevent

Remediating the specific flaw in the M.Williamson WordPress theme versions <=1.2.11 directly prevents exploitation of this PHP local file inclusion vulnerability.

SI-10 Information Input Validation good match
prevent

Validating filenames supplied to PHP include/require statements blocks malicious path traversal or inclusion attempts central to this CVE.

CM-6 Configuration Settings partial match
prevent

Securing PHP configuration settings such as open_basedir and allow_url_include=Off limits the impact of improper filename controls in the vulnerable theme.

References