CVE-2026-25369

High

Published: 16 March 2026

Published

16 March 2026

Modified

23 April 2026

KEV Added

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Patch

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CVSS Score v3.1 7.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L

EPSS Score 0.0004 14.4th percentile

Risk Priority 14 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-25369 is a high-severity Cross-site Scripting (CWE-79) vulnerability. Its CVSS base score is 7.1 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Drive-by Compromise (T1189); ranked at the 14.4th 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-15 (Information Output Filtering).

Deeper analysis

CVE-2026-25369 is an Improper Neutralization of Input During Web Page Generation vulnerability, classified as Reflected Cross-site Scripting (XSS) under CWE-79, affecting the Flexmls® IDX WordPress plugin (flexmls-idx). This issue impacts all versions from n/a through 3.15.9, where user input is not properly sanitized during web page generation, allowing malicious scripts to be reflected back to users.

The vulnerability carries a CVSS v3.1 base score of 7.1 (AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L), indicating it is exploitable over the network with low attack complexity, no privileges required, but necessitating user interaction such as clicking a malicious link. Any unauthenticated attacker can craft and distribute payloads that, when processed by the plugin, execute arbitrary JavaScript in the victim's browser context, potentially enabling session hijacking, data theft, or other client-side attacks with low impacts on confidentiality, integrity, and availability across a changed scope.

The Patchstack advisory (https://patchstack.com/database/Wordpress/Plugin/flexmls-idx/vulnerability/wordpress-flexmls-idx-plugin-3-15-9-reflected-cross-site-scripting-xss-vulnerability?_s_id=cve) documents this Reflected XSS in the flexmls-idx WordPress plugin up to version 3.15.9, recommending mitigation through updating to a patched version of the plugin where available.

EU & UK References

🇪🇺 ENISA EUVD: EUVD-2026-12445

Vulnerability details

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in flexmls Flexmls® IDX flexmls-idx allows Reflected XSS.This issue affects Flexmls® IDX: from n/a through <= 3.15.9.

CWE(s): CWE-79

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1189 Drive-by Compromise Initial Access

Adversaries may gain access to a system through a user visiting a website over the normal course of browsing.

attack.mitre.org →

T1185 Browser Session Hijacking Collection

Adversaries may take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify user-behaviors, and intercept information as part of various browser session hijacking techniques.

attack.mitre.org →

T1539 Steal Web Session Cookie Credential Access

An adversary may steal web application or service session cookies and use them to gain access to web applications or Internet services as an authenticated user without needing credentials.

attack.mitre.org →

Why these techniques?

Reflected XSS directly enables arbitrary JS execution in the victim's browser via crafted links to the vulnerable plugin, facilitating drive-by compromise (T1189), browser session hijacking (T1185), and stealing web session cookies (T1539) for data theft or hijacking.

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