CVE-2025-55409

HighPublic PoC

Published: 25 August 2025

Published

25 August 2025

Modified

09 September 2025

KEV Added

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Patch

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CVSS Score 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Score 0.0014 34.4th percentile

Risk Priority 18 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-55409 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Foxcms Foxcms. Its CVSS base score is 8.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 34.4th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-15 (Information Output Filtering).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploit Public-Facing Application (T1190) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-10 Information Input Validation good match

prevent

Validates inputs to /index.php/article preventing injection of malicious scripts characteristic of this XSS vulnerability.

SI-15 Information Output Filtering good match

prevent

Filters and encodes outputs from /index.php/article to block execution of arbitrary code in victims' browsers.

SI-2 Flaw Remediation good match

prevent

Remediates the specific XSS flaw in FoxCMS 1.2.6 through timely patching or code corrections.

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 →

T1059.007 JavaScript Execution

Adversaries may abuse various implementations of JavaScript for execution.

attack.mitre.org →

Why these techniques?

XSS in public-facing CMS component directly enables exploitation of the app (T1190) and arbitrary JavaScript execution in browser (T1059.007).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

FoxCMS 1.2.6, there is a Cross Site Scripting vulnerability in /index.php/article. This allows attackers to execute arbitrary code.

Deeper analysisAI

CVE-2025-55409 is a Cross-Site Scripting (XSS) vulnerability in FoxCMS version 1.2.6, affecting the /index.php/article component. Published on 2025-08-25T16:15:31.590, it carries a CVSS v3.1 base score of 8.8 (AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H) and maps to CWE-79.

The vulnerability can be exploited remotely by unauthenticated attackers over the network with low complexity, requiring user interaction such as viewing a malicious page or clicking a crafted link. Successful exploitation enables attackers to execute arbitrary code in the victim's browser context, resulting in high impacts to confidentiality, integrity, and availability.

Mitigation details are available in advisories referenced at http://foxcms.com and https://www.notion.so/CVE-2025-55409-2222b2fd0210804facb7cfe5d9db1ebd.