CVE-2026-1903: Ravelry Designs Widget XSS Vulnerability

CVE-2026-1903 Overview

The Ravelry Designs Widget plugin for WordPress is vulnerable to Stored Cross-Site Scripting (XSS) via the layout attribute of the sb_ravelry_designs shortcode in all versions up to, and including, 1.0.0. This vulnerability exists due to insufficient input sanitization and output escaping on user-supplied attributes. Authenticated attackers with contributor-level access and above can inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Critical Impact

Authenticated attackers can inject persistent malicious scripts that execute in visitors' browsers, potentially leading to session hijacking, credential theft, or further compromise of WordPress sites.

Affected Products

• Ravelry Designs Widget plugin for WordPress version 1.0.0 and earlier
• WordPress installations using the vulnerable sb_ravelry_designs shortcode
• Sites with contributor-level or higher user accounts

Discovery Timeline

• 2026-02-14 - CVE CVE-2026-1903 published to NVD
• 2026-02-18 - Last updated in NVD database

Technical Details for CVE-2026-1903

Vulnerability Analysis

This Stored Cross-Site Scripting vulnerability stems from improper handling of user input within the sb_ravelry_designs shortcode functionality. When users with contributor-level permissions or higher create or edit content containing the shortcode, the layout attribute value is not adequately sanitized before being rendered on the page.

The vulnerability is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation), which represents a fundamental failure to properly encode output that contains user-controllable data. In this case, the shortcode handler processes the layout parameter and directly includes it in the generated HTML output without sufficient escaping, allowing script injection.

The attack requires network access and low privileges (contributor-level account), but once the malicious payload is stored, it executes automatically for any user viewing the affected page without requiring further interaction.

Root Cause

The root cause of CVE-2026-1903 lies in insufficient input sanitization and output escaping within the shortcode processing logic. The plugin fails to properly validate and sanitize the layout attribute value before incorporating it into the page output. Specifically, the vulnerability is located in the shortcode handler at line 119 of ravelry-designs-widget.php, where user-supplied attribute values are processed without adequate security controls.

WordPress provides numerous functions for escaping output (such as esc_attr(), esc_html(), and wp_kses()), but the plugin does not leverage these protections appropriately for the layout attribute, allowing attackers to break out of the intended context and inject arbitrary JavaScript code.

Attack Vector

The attack vector is network-based and requires authentication with at least contributor-level privileges. An attacker would:

1. Authenticate to the WordPress site with contributor or higher privileges
2. Create or edit a post/page containing the sb_ravelry_designs shortcode
3. Inject malicious JavaScript code through the layout attribute
4. Publish or save the content as a draft (depending on permissions)
5. The malicious script persists in the database and executes whenever any user views the affected page

The attack exploits the shortcode's failure to properly sanitize the layout attribute, allowing script injection that persists across page loads and affects all visitors to the compromised page.

Detection Methods for CVE-2026-1903

Indicators of Compromise

• Presence of unexpected JavaScript code within posts or pages containing the sb_ravelry_designs shortcode
• Anomalous layout attribute values containing script tags, event handlers, or encoded JavaScript
• Unusual network requests originating from pages that use the Ravelry Designs Widget
• Reports from users experiencing unexpected browser behavior or redirects when viewing specific pages

Detection Strategies

• Review WordPress database for posts containing sb_ravelry_designs shortcodes with suspicious layout attribute values
• Implement Content Security Policy (CSP) headers to detect and block unauthorized inline script execution
• Deploy web application firewalls (WAF) with rules to detect XSS payloads in shortcode attributes
• Monitor WordPress audit logs for content modifications by contributor-level users that include the vulnerable shortcode

Monitoring Recommendations

• Enable comprehensive WordPress activity logging to track shortcode usage and content modifications
• Configure SentinelOne to monitor for suspicious JavaScript execution patterns on WordPress sites
• Implement real-time alerting for changes to posts or pages containing the Ravelry Designs Widget shortcode
• Regularly scan the WordPress database for known XSS patterns within shortcode attributes

How to Mitigate CVE-2026-1903

Immediate Actions Required

• Disable or deactivate the Ravelry Designs Widget plugin until a patched version is available
• Audit all existing posts and pages for potentially malicious content in sb_ravelry_designs shortcodes
• Review and restrict contributor-level access to trusted users only
• Implement a Web Application Firewall (WAF) with XSS protection rules as an additional defense layer

Patch Information

As of the last update on 2026-02-18, no official patch has been confirmed. Site administrators should monitor the WordPress Plugin Source Code and the Wordfence Vulnerability Report for updates regarding a security fix. The vulnerable code is located at line 119 of the plugin.

Workarounds

• Completely deactivate the Ravelry Designs Widget plugin until a security update is released
• Remove all existing instances of the sb_ravelry_designs shortcode from site content
• Restrict user permissions to prevent contributor-level accounts from publishing content directly
• Implement strict Content Security Policy headers to mitigate the impact of any stored XSS payloads

# WordPress CLI command to deactivate the vulnerable plugin
wp plugin deactivate ravelry-designs-widget

# Search for potentially affected posts in the WordPress database
wp db query "SELECT ID, post_title FROM wp_posts WHERE post_content LIKE '%sb_ravelry_designs%'"