CVE-2026-121976: XSS (CVSS 6.4)

Description

The Modula plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'items' parameter in versions up to, and including, 3.0.17 This is due to insufficient input sanitization of the per-image 'link' field in the save_merged_items() REST handler and Images\Adapter::normalize_item_row(), which preserves unknown keys verbatim, combined with output escaping in Modula_Helper::generate_attributes() that applies only esc_attr() to the resulting anchor href and does not strip the 'javascript:' URL scheme. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page and clicks the gallery tile.

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CVSS v3.1 Score

6.4

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

EPSS — Exploit Prediction

0.0032

Probability of exploitation

0.25%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-79 Cross-site Scripting (XSS)

References

Other References

https://plugins.trac.wordpress.org/browser/modula-best-grid-gallery/ https://plugins.trac.wordpress.org/browser/modula-best-grid-gallery/tags/3.0.17/includes/core/helpers/class-modula-helper.php#L17 https://plugins.trac.wordpress.org/browser/modula-best-grid-gallery/tags/3.0.17/includes/public/shortcode/class-modula-item-data-processor.php#L629 https://plugins.trac.wordpress.org/browser/modula-best-grid-gallery/tags/3.0.17/includes/v2/class-meta-sync.php#L422 https://plugins.trac.wordpress.org/browser/modula-best-grid-gallery/tags/3.0.17/includes/v2/images/class-adapter.php#L655 https://plugins.trac.wordpress.org/browser/modula-best-grid-gallery/tags/3.0.17/includes/v2/rest/class-gallery-upload-controller.php#L914 https://plugins.trac.wordpress.org/changeset?reponame=&new=3787971%40modula-best-grid-gallery%2Ftags%2F3.0.18&old=3781958%40modula-best-grid-gallery%2Ftags%2F3.0.17 https://www.wordfence.com/threat-intel/vulnerabilities/id/91d3cbc2-00ca-4384-a52d-84fe2f0328b3?source=cve

Frequently Asked Questions

What is CVE-2026-121976? +

The Modula plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'items' parameter in versions up to, and including, 3.0.17 This is due to insufficient input sanitization of the per-image 'link' field in the save_merged_items() REST handler and Images\Adapter::normalize_item_row(), which preserves unknown keys verbatim, combined with output escaping in Modula_Helper::generate_attributes() that applies only esc_attr() to the resulting anchor href and does not strip the 'javascript:' URL scheme. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page and clicks the gallery tile. It has a CVSS v3.1 base score of 6.4 (MEDIUM).

How severe is CVE-2026-121976? +

CVE-2026-121976 has a CVSS v3.1 score of 6.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0032, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-121976? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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