What is the CVSS score of CVE-2026-0894?

CVE-2026-0894 has a CVSS 3.1 base score of 6.4 (Medium). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N. EPSS exploitation probability: 0.0%.

WordPress CVE-2026-0894

EUVD-2026-23670 MEDIUM

Cross-site Scripting (XSS) (CWE-79)

2026-04-18 Wordfence

XSS WordPress

6.4

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

6.4 MEDIUM

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

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Analysis Generated

Apr 18, 2026 - 09:49 vuln.today

EUVD ID Assigned

Apr 18, 2026 - 09:30 euvd

EUVD-2026-23670

Analysis Generated

Apr 18, 2026 - 09:30 vuln.today

CVE Published

Apr 18, 2026 - 09:26 nvd

MEDIUM 6.4

DescriptionCVE.org

The Content Blocks (Custom Post Widget) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's content_block shortcode in all versions up to, and including, 3.3.9 due to insufficient input sanitization and output escaping on user supplied values consumed from user-created content blocks. 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.

AnalysisAI

Stored Cross-Site Scripting in Content Blocks (Custom Post Widget) plugin for WordPress affects all versions up to 3.3.9, allowing authenticated contributors and above to inject arbitrary JavaScript via the content_block shortcode that executes in the browsers of all users viewing affected pages. The vulnerability stems from insufficient input sanitization and output escaping; no public exploit code or active exploitation has been identified at the time of analysis, but the low attack complexity and broad scope (cross-site) make this a significant risk for WordPress sites with untrusted contributor accounts.

Technical ContextAI

The Content Blocks (Custom Post Widget) plugin extends WordPress functionality through custom shortcodes, specifically the content_block shortcode, which dynamically renders user-supplied content. The underlying weakness (CWE-79: Improper Neutralization of Input During Web Page Generation) indicates the plugin fails to properly sanitize user input before storage (stored XSS vector) or escape output when rendering shortcode content, violating WordPress security best practices via the sanitize_text_field() and wp_kses_post() functions. The CPE identifier cpe:2.3:a:vanderwijk:content_blocks_(custom_post_widget) confirms the affected product is maintained by vanderwijk and distributed through the official WordPress plugin repository.

RemediationAI

Upgrade the Content Blocks (Custom Post Widget) plugin to version 3.4.0 or later, which includes patches for input sanitization and output escaping. Administrators should navigate to the WordPress Plugins dashboard, locate the Content Blocks plugin, and apply the update immediately. For organizations unable to update immediately, restrict the 'contributor' and 'author' WordPress role permissions to prevent creation or editing of content blocks via the 'content_block' shortcode capability (via role editor plugins such as User Role Editor), or temporarily disable the plugin if not actively in use. A secondary mitigation is to audit all existing content blocks created before the patch for injected scripts and remove suspicious shortcodes, though this is labor-intensive for sites with many blocks. Disable the plugin entirely if contributor-level users are untrusted or if custom code review is unavailable.