CVE-2025-23840
Published: 17 February 2025
Summary
CVE-2025-23840 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 Exploit Public-Facing Application (T1190); ranked at the 25.2th 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-2025-23840 is an Improper Neutralization of Input During Web Page Generation vulnerability, classified as reflected cross-site scripting (XSS) under CWE-79. It affects the WP-NOTCAPTCHA WordPress plugin by webjema WP-NOTCAPTCHA wp-notcaptcha, impacting all versions from n/a through 1.3.1.
The vulnerability carries a CVSS v3.1 base score of 7.1 (High) with the vector AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L. Remote attackers require no privileges and can exploit it over the network with low attack complexity, though it demands user interaction such as clicking a malicious link. Exploitation enables limited impacts on confidentiality, integrity, and availability, with a changed scope that may affect other users or resources via the injected script executing in the victim's browser context.
The Patchstack advisory at https://patchstack.com/database/Wordpress/Plugin/wp-notcaptcha/vulnerability/wordpress-wp-notcaptcha-plugin-1-3-1-reflected-cross-site-scripting-xss-vulnerability?_s_id=cve documents the reflected XSS flaw in WP-NOTCAPTCHA version 1.3.1 and serves as the primary reference for mitigation details.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-4876
Vulnerability details
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in webjema WP-NOTCAPTCHA wp-notcaptcha allows Reflected XSS.This issue affects WP-NOTCAPTCHA: from n/a through <= 1.3.1.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Reflected XSS in public-facing WordPress plugin directly enables remote exploitation of web applications (T1190) and arbitrary JavaScript execution in victim browser context via malicious link (T1059.007).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly addresses the reflected XSS flaw by requiring timely patching and remediation of the vulnerable WP-NOTCAPTCHA plugin versions <=1.3.1.
Mandates validation of user inputs to the web plugin, preventing injection of malicious scripts that lead to reflected XSS.
Requires filtering and encoding of reflected outputs in web page generation to neutralize XSS payloads before rendering in the victim's browser.