CVE-2026-2121
Weaver Show Posts <= 1.8.1 - Authenticated (Administrator+) Stored Cross-Site Scripting via 'Additional Classes to Wrap Posts' Widget Setting
Description
The Weaver Show Posts plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'add_class' parameter in all versions up to, and including, 1.8.1. This is due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with Administrator-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This primarily affects multisite installations where Administrators do not have the unfiltered_html capability.
INFO
Published Date :
March 21, 2026, 4:16 a.m.
Last Modified :
March 21, 2026, 4:16 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Update the Weaver Show Posts plugin.
- Verify input sanitization and output escaping.
- Restrict administrator access if possible.
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-2026-2121.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-2121 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-2026-2121
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-2026-2121 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-2121 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.
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New CVE Received by [email protected]
Mar. 21, 2026
Action Type Old Value New Value Added Description The Weaver Show Posts plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'add_class' parameter in all versions up to, and including, 1.8.1. This is due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with Administrator-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This primarily affects multisite installations where Administrators do not have the unfiltered_html capability. Added CVSS V3.1 AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N Added CWE CWE-79 Added Reference https://plugins.trac.wordpress.org/browser/show-posts/tags/1.8.1/includes/posts-widgets.php#L32 Added Reference https://plugins.trac.wordpress.org/browser/show-posts/tags/1.8.1/includes/posts-widgets.php#L45 Added Reference https://plugins.trac.wordpress.org/browser/show-posts/trunk/includes/posts-widgets.php#L32 Added Reference https://plugins.trac.wordpress.org/browser/show-posts/trunk/includes/posts-widgets.php#L45 Added Reference https://www.wordfence.com/threat-intel/vulnerabilities/id/e0d525ab-a86d-4750-9d16-731cbc0a626e?source=cve Added Reference https://youtu.be/kbSqUuEAyho