Cyber Resilience

CVE-2026-22420

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 0.0050 39.1th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-22420 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 39.1th 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-2026-22420 is an Improper Control of Filename for Include/Require Statement in PHP Program vulnerability, classified as a PHP Remote File Inclusion issue that enables PHP Local File Inclusion in the AncoraThemes Horizon WordPress theme. The vulnerability affects Horizon versions from n/a through 1.1 inclusive, as documented with CWE-98 and published on 2026-03-05.

The vulnerability can be exploited by unauthenticated attackers (PR:N) over the network (AV:N) with high attack complexity (AC:H) and no user interaction required (UI:N). Successful exploitation results in high impacts across confidentiality, integrity, and availability (C:H/I:H/A:H), yielding a CVSS v3.1 base score of 8.1 and potential for unauthorized file access or manipulation on the affected system.

Mitigation details are available in the Patchstack advisory at https://patchstack.com/database/Wordpress/Theme/horizon/vulnerability/wordpress-horizon-theme-1-1-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 AncoraThemes Horizon horizon allows PHP Local File Inclusion.This issue affects Horizon: from n/a through <= 1.1.

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 →
Why these techniques?

CVE-2026-22420 is a Local File Inclusion vulnerability in a public-facing WordPress theme, directly enabling exploitation of a public-facing web application.

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

CVEs Like This One

CVE-2025-58923Shared CWE-98
CVE-2025-69057Shared CWE-98
CVE-2024-54263Shared CWE-98
CVE-2026-28035Shared CWE-98
CVE-2026-28024Shared CWE-98
CVE-2025-67525Shared CWE-98
CVE-2025-22707Shared CWE-98
CVE-2025-69375Shared CWE-98
CVE-2026-22443Shared CWE-98
CVE-2025-53198Shared CWE-98

Affected Assets

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match
prevent

Directly requires validation of untrusted inputs like filenames in PHP include/require statements to prevent local file inclusion attacks as in CVE-2026-22420.

SI-2 Flaw Remediation good match
prevent

Mandates timely patching and remediation of known flaws such as the PHP file inclusion vulnerability in the Horizon WordPress theme up to version 1.1.

CM-6 Configuration Settings partial match
prevent

Enforces secure PHP configuration settings like open_basedir restrictions or disabling dangerous functions to limit the impact of file inclusion vulnerabilities.

References