CVE-2026-96840 json
Post Grid Gutenberg Blocks <= 5.1.0 - Unauthenticated Stored Cross-Site Scripting via display_name User Field
published 2026-10-10 30 d ago modified 2026-10-13 26 d ago also EUVD-2026-96224
- cvss
- 7.2
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.2%
- EPSS 0.2% chance of exploitation in 30 days, percentile 14%
- public exploits
- 0
- none known
Summary
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.
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 28 d ago
Exploit prediction
0.24% chance of exploitation in the next 30 days, higher than 14% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 7.2 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N |
Affected products
- wpxpo Post Grid Gutenberg Blocks – PostX
Classification
- Weakness
-
- CWE-79 Improper Neutralization of Input During Web Page Generation
- Technology feeds
References
- wordfence.com /threat-intel/vulnerabilities/id/39472e87-174c-4abf-bc83-fed0939440af?source=cve
- plugins.trac.wordpress.org /browser/ultimate-post/tags/5.0.41/addons/builder/blocks/Archive_Title.php#L144
- plugins.trac.wordpress.org /browser/ultimate-post/tags/5.0.41/addons/builder/blocks/Archive_Title.php#L98
- wordpress.org /plugins/ultimate-post/
- plugins.trac.wordpress.org /changeset/3727209/ultimate-post/trunk/addons/builder/blocks/Archive_Title.php
Sources
- CVE List CVE-2026-96840
- NVD CVE-2026-96840
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.