Cross-site scripting in wpxpo Post Grid Gutenberg Blocks – PostX
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- Low · Low · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-79.
Summary
The Ultimate Post plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'moreResultsText' block attribute of the ultimate-post/advanced-search block in versions up to and including 5.0.31. This is due to insufficient input sanitization and output escaping in the Advanced_Search::content() render callback: the attribute value is filtered with wp_kses(), which strips disallowed HTML tags but does NOT escape HTML special characters such as double quotes in plain text, and the result is then concatenated directly into the data-viewmoretext HTML attribute without esc_attr(). 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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-13253
- 2026-10-03 Alias added: GHSA-fmqh-3qcq-wcxg
References
Other 8
- https://www.wordfence.com/threat-intel/vulnerabilities/id/070ccd70-22c3-47f1-9dce-a884bff9ea76?source=cve
- https://plugins.trac.wordpress.org/browser/ultimate-post/tags/5.0.27/blocks/Advanced_Search.php#L116
- https://plugins.trac.wordpress.org/browser/ultimate-post/tags/5.0.28/blocks/Advanced_Search.php#L116
- https://plugins.trac.wordpress.org/browser/ultimate-post/tags/5.0.28/blocks/Advanced_Search.php#L108
- https://plugins.trac.wordpress.org/browser/ultimate-post/tags/5.0.28/classes/Blocks.php#L231
- https://plugins.trac.wordpress.org/browser/ultimate-post/tags/5.0.27/blocks/Advanced_Search.php#L108
- https://plugins.trac.wordpress.org/browser/ultimate-post/tags/5.0.27/classes/Blocks.php#L231
- https://plugins.trac.wordpress.org/changeset?reponame=&old=3598669%40ultimate-post&new=3598669%40ultimate-post
More wpxpo vulnerabilities
- TI-2024-09942 PostX <= 4.1.16 - Missing Authorization to Arbitrary Plugin Installation/Activation CVSS 3.1HIGH 8.8
- TI-2024-04008 PostX < 4.1.0 - Contributor+ Stored XSS CVSS 3.1MEDIUM 6.8
- TI-2023-03707 PostX - Gutenberg Post Grid Blocks < 3.0.6 - Reflected Cross-Site Scripting CVSS 3.1MEDIUM 6.1
- TI-2024-20266 WordPress WholesaleX plugin <= 1.3.2 - Unauthenticated Privilege Escalation vulnerability CVSS 3.1CRITICAL 9.8
- TI-2024-19970 WordPress WholesaleX plugin <= 1.3.2 - Unauthenticated PHP Object Injection vulnerability CVSS 3.1CRITICAL 10.0
- TI-2024-15553 WordPress ProductX – Gutenberg WooCommerce Blocks Plugin <= 3.1.4 is vulnerable to PHP Object Injection CVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-13253 · CVE Program
- CVE-2026-13253 · NVD
- FIRST EPSS
- GHSA-fmqh-3qcq-wcxg · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences