PT-2026-33588 · WordPress · Coblocks

Fernando Mecozzi · Published 2026-04-18 · Updated 2026-04-21 · CVE-2026-4801

Positive Technologies (AI Summary)

CVSS v3.1

6.4

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions CoBlocks versions prior to 3.1.17

Description The Page Builder Gutenberg Blocks – CoBlocks plugin for WordPress contains a Stored Cross-Site Scripting issue. This occurs due to insufficient output escaping of event titles, descriptions, and locations fetched from external iCal feeds within the Events block rendering function. Authenticated attackers with Contributor-level access or higher can inject arbitrary web scripts into pages, which then execute when a user visits the affected page.

Recommendations Update the plugin to a version newer than 3.1.16.

Fix

XSS

Weakness Enumeration

CWE-79

Related Identifiers

CVE-2026-4801

Affected Products

Coblocks

References · 17

• https://nvd.nist.gov/vuln/detail/CVE-2026-4801 · Security Note
• https://plugins.trac.wordpress.org/browser/coblocks/trunk/src/blocks/events/index.php#L91 · Note
• https://wordfence.com/threat-intel/vulnerabilities/id/bde0aef3-aa61-4ee7-9cbf-9f51cb5ac700?source=cve · Note
• https://plugins.trac.wordpress.org/browser/coblocks/tags/3.1.16/src/blocks/events/index.php#L245 · Note
• https://plugins.trac.wordpress.org/browser/coblocks/trunk/src/blocks/events/index.php#L218 · Note
• https://plugins.trac.wordpress.org/browser/coblocks/tags/3.1.16/src/blocks/events/index.php#L218 · Note
• https://plugins.trac.wordpress.org/browser/coblocks/trunk/src/blocks/events/index.php#L255 · Note
• https://plugins.trac.wordpress.org/browser/coblocks/trunk/src/blocks/events/index.php#L245 · Note
• https://plugins.trac.wordpress.org/browser/coblocks/tags/3.1.16/src/blocks/events/index.php#L246 · Note
• https://twitter.com/VulmonFeeds/status/2045398837619986926 · Twitter Post
• https://plugins.trac.wordpress.org/browser/coblocks/trunk/src/blocks/events/index.php#L246 · Note
• https://twitter.com/CVEnew/status/2045467324187127817 · Twitter Post
• https://plugins.trac.wordpress.org/changeset?old_path=%2Fcoblocks/tags/3.1.16&new_path=%2Fcoblocks/tags/3.1.17 · Note
• https://plugins.trac.wordpress.org/changeset/3475789/coblocks/trunk/src/blocks/events/index.php · Note
• https://plugins.trac.wordpress.org/browser/coblocks/tags/3.1.16/src/blocks/events/index.php#L91 · Note