CVE-2026-2121
Weaver Show Posts <= 1.8.1 - Authenticated (Administrator+) Stored Cross-Site Scripting via 'Additional Classes to Wrap Posts' Widget Setting
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
Weaver Show Posts <= 1.8.1 - Authenticated (Administrator+) Stored Cross-Site Scripting via 'Additional Classes to Wrap Posts' Widget Setting
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.
- Record
CVE-2026-2121- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2026-14151
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.
- Record
EUVD-2026-14151- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-qf9c-wfj4-w8fw
The Weaver Show Posts plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ...
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.
- Record
GHSA-qf9c-wfj4-w8fw- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2026-2121- CVSS 3.1
- 4.4 Medium
CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-2121 is a medium vulnerability (CVSS 4.4) in Wpweaver Weaver Show Posts, published March 21, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.21%, the 11th percentile. No source names a fixed version.
References
wordfence.com/threat-intel/vulnerabilities/id/e0d525ab-a86d-4750-9d16-731cbc0a626e?source=cve
plugins.trac.wordpress.org/browser/show-posts/trunk/includes/posts-widgets.php
youtu.be/kbSqUuEAyho
nvd.nist.gov/vuln/detail/CVE-2026-2121
github.com/advisories/GHSA-qf9c-wfj4-w8fw