CVE-2026-2121
Stored XSS in Weaver Show Posts Plugin Allows Admin Script Injection
Publication date: 2026-03-21
Last updated on: 2026-03-21
Assigner: Wordfence
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| weaver_show_posts | weaver_show_posts | to 1.8.1 (inc) |
| weaver | show_posts | to 1.8.1 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-79 | The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. |
Attack-Flow Graph
AI Powered Q&A
How does this vulnerability affect compliance with common standards and regulations (like GDPR, HIPAA)?:
I don't know
Can you explain this vulnerability to me?
The Weaver Show Posts plugin for WordPress has a Stored Cross-Site Scripting (XSS) vulnerability in all versions up to and including 1.8.1. This vulnerability arises because the plugin does not properly sanitize or escape user-supplied input in the 'add_class' parameter. As a result, authenticated users with Administrator-level access or higher can inject arbitrary malicious scripts into pages. These scripts will execute whenever any user accesses the affected page.
This issue mainly affects multisite WordPress installations where Administrators lack the unfiltered_html capability, allowing them to exploit this vulnerability.
How can this vulnerability impact me? :
This vulnerability can allow attackers with Administrator-level access to inject malicious scripts into web pages. These scripts execute in the browsers of users who visit the infected pages, potentially leading to unauthorized actions such as stealing session cookies, redirecting users to malicious sites, or performing actions on behalf of users without their consent.
Because the vulnerability is a Stored Cross-Site Scripting issue, the malicious code persists on the site and affects all users who view the compromised content.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability involves Stored Cross-Site Scripting (XSS) via the 'add_class' parameter in the Weaver Show Posts WordPress plugin. Detection typically requires inspecting the plugin's usage of the 'add_class' parameter in widget settings or posts where administrators have injected malicious scripts.
Since the vulnerability requires Administrator-level access to exploit, detection can involve reviewing widget configurations for suspicious or unexpected script tags or payloads in the 'add_class' field.
There are no specific commands provided in the available resources or CVE description to detect this vulnerability on your network or system.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, immediately update the Weaver Show Posts plugin to a version later than 1.8.1 where the issue is fixed, if available.
If an update is not yet available, restrict Administrator-level access to trusted users only, as exploitation requires such privileges.
Additionally, review and sanitize any input in the 'add_class' parameter fields in widget settings to ensure no malicious scripts are present.
Consider disabling or removing the Weaver Show Posts plugin temporarily if the risk is high and no patch is available.