What is CVE-2026-2121?

CVE-2026-2121 is a medium-severity vulnerability in Wpweaver Weaver Show Posts, classified under Cross-site Scripting. CVSS score: 4.4/10. Published 2026-03-21.

How severe is CVE-2026-2121?

Medium severity. CVSS v3 base score is 4.4 out of 10.

XSS in Wpweaver Weaver Show Posts

CVE-2026-2121

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.

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (10.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.4 (Medium). Vector: 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 — versions 0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

Frequently asked questions

What is CVE-2026-2121?: CVE-2026-2121 is a medium-severity vulnerability in Wpweaver Weaver Show Posts, classified under Cross-site Scripting. CVSS score: 4.4/10. Published 2026-03-21.
How severe is CVE-2026-2121?: Medium severity. CVSS v3 base score is 4.4 out of 10.