CVE-2026-6378 | Maxi Blocks <= 2.1.9 - Authenticated (Author+) Stored Cross-Site Scripting via Style Card REST API

The Maxi Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the `/wp-json/maxi-blocks/v1.0/style-card` REST API endpoint in all versions up to, and including, 2.1.9 due to insufficient input sanitization and output escaping of the `sc_styles` parameter. This makes it possible for authenticated attackers, with Author-level access and above, to inject arbitrary web scripts that execute on every page where the plugin's style card styles are loaded, including across the entire WordPress admin panel.

Published: 2026-05-02 Last update: 2026-05-05 Assigner: [email protected] Source: [email protected]
NVD Status：Deferred，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-6378 is rated Low Risk (31.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.06%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-6378

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-02 — 0.06% —

Full EPSS history (1 record total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-6378

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.4 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 3.1 2.7 [email protected]

Weakness enumeration for CVE-2026-6378

GitHub Security Advisory for CVE-2026-6378

GHSA-8p3w-9597-pwh9 · Severity: medium — The Maxi Blocks plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the `/wp...

Affected software / configurations for CVE-2026-6378

Vendor Product Version Raw CPE
No affected products in dataset.

References for CVE-2026-6378

URL Tags
https://github.com/maxi-blocks/maxi-blocks/pull/6250/changes/8db3267df9858f684e420566227ed2ea7954d9a9
https://plugins.trac.wordpress.org/browser/maxi-blocks/tags/2.1.10/core/class-maxi-api.php#L1010
https://plugins.trac.wordpress.org/browser/maxi-blocks/tags/2.1.10/core/class-maxi-api.php#L1021
https://plugins.trac.wordpress.org/browser/maxi-blocks/tags/2.1.10/core/class-maxi-api.php#L979
https://plugins.trac.wordpress.org/browser/maxi-blocks/tags/2.1.10/core/class-maxi-api.php#L981
https://plugins.trac.wordpress.org/browser/maxi-blocks/tags/2.1.10/core/class-maxi-api.php#L987
https://plugins.trac.wordpress.org/browser/maxi-blocks/tags/2.1.9/core/class-maxi-api.php#L221
https://plugins.trac.wordpress.org/browser/maxi-blocks/tags/2.1.9/core/class-maxi-api.php#L979
https://plugins.trac.wordpress.org/browser/maxi-blocks/tags/2.1.9/core/class-maxi-style-cards.php#L197
https://www.wordfence.com/threat-intel/vulnerabilities/id/22f05048-df38-4f26-82a3-53caac995283?source=cve
cvelogic Threat Intelligence