CVE-2026-4081

CVE-2026-4081 is a medium-severity vulnerability with a CVSS 3.x base score of 6.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Description

The ZeM STL plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the [zemstl] shortcode in all versions up to and including 1.0. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes, specifically the 'url', 'color', and 'bgcolor' parameters. These attribute values are directly interpolated into HTML attribute context without being passed through esc_attr() or any other escaping function. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Frequently asked questions

What is CVE-2026-4081?
The ZeM STL plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the [zemstl] shortcode in all versions up to and including 1.0. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes, specifically the 'url', 'color', and 'bgcolor' parameters. These attribute values are directly interpolated into HTML attribute context without being passed through esc_attr() or any other escaping function. This makes it possible for authenticated attackers, with Contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
How severe is CVE-2026-4081?
CVE-2026-4081 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2026-4081 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (15th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-4081?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-4081 have an EU (EUVD) identifier?
Yes. CVE-2026-4081 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-33885.
When was CVE-2026-4081 published?
CVE-2026-4081 was published on 2026-06-02 and last updated on 2026-06-17.

References

Other CWE-79 (Cross-site Scripting (XSS)) vulnerabilities

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