CVE-2026-96840

high

Description

The Post Grid Gutenberg Blocks – PostX plugin for WordPress is vulnerable to Stored Cross-Site Scripting via display_name User Field in all versions up to, and including, 5.1.0 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. WordPress core's pre_user_display_name filter encodes &, <, and > but leaves double-quotes intact (ENT_NOQUOTES), allowing a Subscriber-level user to store a double-quote in their display_name via /wp-admin/profile.php that subsequently breaks out of the alt="" attribute at Archive_Title.php:144.

References

https://www.wordfence.com/threat-intel/vulnerabilities/id/39472e87-174c-4abf-bc83-fed0939440af?source=cve

https://wordpress.org/plugins/ultimate-post/

https://plugins.trac.wordpress.org/changeset/3727209/ultimate-post/trunk/addons/builder/blocks/Archive_Title.php

https://plugins.trac.wordpress.org/browser/ultimate-post/tags/5.0.41/addons/builder/blocks/Archive_Title.php#L98

https://plugins.trac.wordpress.org/browser/ultimate-post/tags/5.0.41/addons/builder/blocks/Archive_Title.php#L144

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-96224

Details

Source: Mitre, NVD

Published: 2026-10-10

Updated: 2026-10-13

Risk Information

CVSS v2

Base Score: 6.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:N

Severity: Medium

CVSS v3

Base Score: 7.2

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

Severity: High

EPSS

EPSS: 0.00236