CVE-2026-13253 json
Post Grid Gutenberg Blocks for News, Magazines, Blog Websites <= 5.0.31 - Authenticated (Contributor+) Stored Cross-Site Scripting via 'moreResultsText' Block Attribute
published 2026-07-09 4 mo ago modified 2026-07-09 4 mo ago also EUVD-2026-42520
- cvss
- 6.4
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 29%
- public exploits
- 0
- none known
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.
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 4 mo ago
Exploit prediction
0.36% chance of exploitation in the next 30 days, higher than 29% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.4 | CVSS:3.1/AV:N/AC:L/PR:L/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/070ccd70-22c3-47f1-9dce-a884bff9ea76?source=cve
- plugins.trac.wordpress.org /browser/ultimate-post/tags/5.0.27/blocks/Advanced_Search.php#L116
- plugins.trac.wordpress.org /browser/ultimate-post/tags/5.0.28/blocks/Advanced_Search.php#L116
- plugins.trac.wordpress.org /browser/ultimate-post/tags/5.0.28/blocks/Advanced_Search.php#L108
- plugins.trac.wordpress.org /browser/ultimate-post/tags/5.0.28/classes/Blocks.php#L231
- plugins.trac.wordpress.org /browser/ultimate-post/tags/5.0.27/blocks/Advanced_Search.php#L108
- plugins.trac.wordpress.org /browser/ultimate-post/tags/5.0.27/classes/Blocks.php#L231
- plugins.trac.wordpress.org /changeset?reponame=&old=3598669%40ultimate-post&new=3598669%40ultimate-post
Sources
- CVE List CVE-2026-13253
- NVD CVE-2026-13253
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.