CVE-2026-2121 json
Weaver Show Posts <= 1.8.1 - Authenticated (Administrator+) Stored Cross-Site Scripting via 'Additional Classes to Wrap Posts' Widget Setting
published 2026-03-21 7 mo ago modified 2026-06-17 4 mo ago also EUVD-2026-14151
- cvss
- 4.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 12%
- public exploits
- 0
- none known
Summary
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.
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 7 mo ago
Exploit prediction
0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 4.4 | CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N |
Affected products
- wpweaver Weaver Show Posts
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
- Technology feeds
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#L32
- plugins.trac.wordpress.org /browser/show-posts/tags/1.8.1/includes/posts-widgets.php#L32
- plugins.trac.wordpress.org /browser/show-posts/trunk/includes/posts-widgets.php#L45
- plugins.trac.wordpress.org /browser/show-posts/tags/1.8.1/includes/posts-widgets.php#L45
- youtu.be /kbSqUuEAyho
Sources
- CVE List CVE-2026-2121
- NVD CVE-2026-2121
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.