CVE-2026-16145
Invisible Anti-Spam & CAPTCHA <= 5.1 - Unauthenticated Stored Cross-Site Scripting via 'action' Parameter
Description
The Invisible Anti-Spam & CAPTCHA — reCAPTCHA Alternative for All Forms plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'action' parameter in all versions up to, and including, 5.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The stored payload is written by any unauthenticated admin-ajax.php request whose action value matches an entry in the plugin's explicit-actions list, which is auto-populated for common form builders at activation and requires no authentication gate to reach the save path.
INFO
Published Date :
Aug. 15, 2026, 4:18 a.m.
Last Modified :
Aug. 20, 2026, 12:48 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-16145
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update The Invisible Anti-Spam & CAPTCHA plugin.
- Ensure input sanitization and output escaping.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-16145.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-16145 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-16145
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-16145 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-16145 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Aug. 18, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-16145', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'partial'}], 'version': '2.0.3', 'timestamp': '2026-08-18T19:38:41.974606Z'} -
New CVE Received by [email protected]
Aug. 15, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'matthiasnordwig', 'product': 'Invisible Anti-Spam & CAPTCHA — reCAPTCHA Alternative for All Forms', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'semver', 'lessThanOrEqual': '5.1'}], 'defaultStatus': 'unaffected'}] Added Description The Invisible Anti-Spam & CAPTCHA — reCAPTCHA Alternative for All Forms plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'action' parameter in all versions up to, and including, 5.1 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The stored payload is written by any unauthenticated admin-ajax.php request whose action value matches an entry in the plugin's explicit-actions list, which is auto-populated for common form builders at activation and requires no authentication gate to reach the save path. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N Added CWE CWE-79 Added Reference https://plugins.trac.wordpress.org/browser/gdpr-compliant-recaptcha-for-all-forms/tags/5.0/includes/class-message-page.php#L621 Added Reference https://plugins.trac.wordpress.org/browser/gdpr-compliant-recaptcha-for-all-forms/tags/5.0/includes/class-stamp.php#L136 Added Reference https://plugins.trac.wordpress.org/browser/gdpr-compliant-recaptcha-for-all-forms/tags/5.0/includes/class-stamp.php#L771 Added Reference https://plugins.trac.wordpress.org/changeset/3633500/gdpr-compliant-recaptcha-for-all-forms Added Reference https://www.wordfence.com/threat-intel/vulnerabilities/id/ff1d2bd8-cc46-4763-8ba7-832b982ff56a?source=cve