Page Builder Gutenberg Blocks <= 3.1.16 - Authenticated (Contributor+) Stored Cross-Site Scripting via External iCal Feed Data

Summary

CVE	CVE-2026-4801
State	PUBLISHED
Assigner	Wordfence
Source Priority	CVE Program / NVD first with legacy fallback
Published	2026-04-18 05:16:23 UTC
Updated	2026-04-22 20:22:50 UTC
Description	The Page Builder Gutenberg Blocks – CoBlocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via external iCal feed data in all versions up to, and including, 3.1.16 due to insufficient output escaping of event titles, descriptions, and locations fetched from external iCal feeds in the Events block rendering 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.

Risk And Classification

Primary CVSS: v3.1 6.4 MEDIUM from [email protected]

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

EPSS: 0.000160000 probability, percentile 0.034990000 (date 2026-04-22)

Problem Types: CWE-79 | CWE-79 CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Version	Source	Type	Score	Severity	Vector
3.1	[email protected]	Primary	6.4	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N`
3.1	CNA	DECLARED	6.4	MEDIUM	`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N`

CVSS v3.1 Breakdown

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

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

Vendor Declared Affected Products

Source	Vendor	Product	Version	Platforms
CNA	Godaddy	Page Builder Gutenberg Blocks CoBlocks	affected 3.1.16 semver	Not specified

References

Reference	Source	Link	Tags
plugins.trac.wordpress.org/browser/coblocks/trunk/src/blocks/events/index.php	[email protected]	plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/coblocks/tags/3.1.16/src/blocks/events/index.php	[email protected]	plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/coblocks/trunk/src/blocks/events/index.php	[email protected]	plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/coblocks/tags/3.1.16/src/blocks/events/index.php	[email protected]	plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/coblocks/trunk/src/blocks/events/index.php	[email protected]	plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/coblocks/trunk/src/blocks/events/index.php	[email protected]	plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/coblocks/tags/3.1.16/src/blocks/events/index.php	[email protected]	plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/coblocks/tags/3.1.16/src/blocks/events/index.php	[email protected]	plugins.trac.wordpress.org
www.wordfence.com/threat-intel/vulnerabilities/id/bde0aef3-aa61-4ee7-9cbf-9f51c...	[email protected]	www.wordfence.com
plugins.trac.wordpress.org/browser/coblocks/tags/3.1.16/src/blocks/events/index.php	[email protected]	plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/coblocks/trunk/src/blocks/events/index.php	[email protected]	plugins.trac.wordpress.org
plugins.trac.wordpress.org/changeset	[email protected]	plugins.trac.wordpress.org
plugins.trac.wordpress.org/changeset/3475789/coblocks/trunk/src/blocks/events/index.php	[email protected]	plugins.trac.wordpress.org
CVE Program record	CVE.ORG	www.cve.org	canonical
NVD vulnerability detail	NVD	nvd.nist.gov	canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: Fernando Mecozzi (en)

Additional Advisory Data

Source	Time	Event
CNA	2026-04-17T14:48:43.000Z	Disclosed

There are currently no legacy QID mappings associated with this CVE.