Vulnerability Alert: Stored XSS in Easy Author Image Plugin (≤ 1.7) — What You Need to Know

Published: 23 Feb 2026

Severity: Medium (CVSS 6.5) — CVE-2026-1373

As a Hong Kong security expert monitoring the WordPress ecosystem, I am issuing this advisory for site owners, administrators and developers. This notice explains the nature of the vulnerability, realistic attack scenarios, detection techniques, containment actions, and practical mitigations you can apply immediately. Vendor-specific recommendations have been intentionally omitted; the guidance below is vendor-neutral and focused on actionable security controls.

Executive summary

• What: Stored Cross‑Site Scripting (XSS) in Easy Author Image plugin (≤ 1.7). The profile picture URL field is not properly sanitized before being stored and later rendered.
• Who can trigger it: Any authenticated user with the Subscriber role can submit a crafted profile picture URL containing a malicious payload.
• Impact: Stored XSS — when the payload is rendered in pages or admin screens that display the profile image/URL (front-end author boxes, admin user lists, comment author previews, etc.), the script may execute in the victim’s browser, leading to session theft, unauthorized actions, data exfiltration or malware delivery.
• CVE: CVE-2026-1373
• CVSS: 6.5 (Medium)
• Official patch: At time of publication there is no universal patched release available for all affected sites.
• Immediate mitigation: Deactivate or remove the plugin where feasible, restrict Subscriber profile editing, clean suspicious values from the database, and consider perimeter protections (WAF/virtual patching) while you evaluate a long-term remediation.

Why this matters — attack scenarios

Stored XSS is particularly dangerous because a malicious script saved in the database can affect many users without further interaction by the attacker. Realistic scenarios include:

1. An attacker with a Subscriber account sets their profile picture URL to a JavaScript payload. When an administrator views the Users list or any admin page that renders the user image/URL, the script executes in the admin’s browser and can exfiltrate session tokens or perform actions using the admin session.
2. The payload is displayed on the public site (author bio or post author widget). Visitors or logged-in users with privileges may execute the payload, enabling site compromise, defacement or redirects to phishing pages.
3. The attacker uses DOM techniques within the payload to modify admin pages, inject further malicious content, or silently manipulate settings using AJAX endpoints accessible to admin roles.

Because the vulnerable input is commonly rendered in multiple contexts, an attacker only needs Subscriber access to achieve significant impact.

Technical overview

The plugin stores and later renders the “profile picture URL” provided by users. The vulnerability occurs when:

• The plugin does not properly sanitize or validate the URL field before saving.
• Stored data is output into HTML without correct escaping for the output context.
• Rendered contexts allow JavaScript execution (for example, unescaped attribute values or insertion of raw HTML).

Typical unsafe coding patterns include echoing stored meta values directly into markup without using esc_url/esc_attr/esc_html, and allowing data URIs, javascript: URIs or embedded HTML to be stored.

High-level proof-of-concept payloads (do NOT test on production or third-party sites you do not own)

• javascript: scheme — may trigger when a URL is used as an anchor or image src (browser behaviour varies).
• Attribute injection: “/onerror=” — if the value is placed in an attribute without proper quoting/escaping.
• Inline HTML injection: <img src=x onerror=> — if stored value is inserted directly into HTML.

This is classified as stored XSS because the attack vector is saved to the site database and executed later.

How an attacker might obtain Subscriber access

The vulnerability assumes control of a Subscriber account. Common paths to obtain such access include:

• Open registration on the site.
• Comment-to-account flows or custom registration systems.
• Compromised credentials due to reuse or weak passwords.
• Third-party registration integrations or social logins with weak controls.

If your site allows registration or low-privilege onboarding, treat all Subscriber-provided fields as untrusted input.

Immediate detection — signs your site may be attacked

Look for these indicators:

• User profile picture URL values containing unexpected tokens: <, >, javascript:, data:, onerror=, onload=, or encoded equivalents.
• Browser console errors or page anomalies when loading users list or author archives.
• Unusual outgoing requests originating from admin browsers following profile view actions.
• HTTP logs showing POSTs to profile update endpoints with script tags or URL scheme injections.
• Perimeter logs (WAF or reverse-proxy) indicating blocked or suspicious POST data.

Example searches (perform on backups or staging copies; always backup before querying or editing live data):

SELECT ID, user_login, meta_key, meta_value FROM wp_usermeta WHERE meta_key LIKE '%profile%' AND meta_value LIKE '%<script%';

wp user meta list <user_id> --format=json | jq . | grep -i "<script"

If you find stored payloads, treat the site as potentially compromised and follow incident response steps below.

Containment and immediate mitigation (practical steps)

If you cannot immediately remove the plugin, apply the following quick actions to reduce exposure:

1. Restrict user editing:

   Temporarily prevent Subscribers from editing profile fields using a capability filter or a small mu-plugin. Example snippet (site-specific plugin or mu-plugin):

   add_action('admin_init', function() {
       if (!current_user_can('edit_users') && !current_user_can('manage_options')) {
           // Remove plugin-specific profile field callbacks; replace callback names if known
           remove_action('show_user_profile', 'your_plugin_profile_fields_callback');
           remove_action('edit_user_profile', 'your_plugin_profile_fields_callback');
       }
   });

   Replace the callback name with the plugin-specific hook if known. If unsure, deactivate the plugin until a safe fix is available.

2. Deactivate the plugin:

   If business requirements permit, deactivate Easy Author Image until the developer releases a secure update. This is the most reliable immediate action.

3. Clean suspicious profile values:

   Identify and remove or sanitize profile picture URL values containing suspicious tokens. Backup the database first and then update via WP-CLI or SQL.

4. Restrict registration and remove spam accounts:

   Disable public registration temporarily and remove low-activity or suspicious Subscriber accounts.

5. Monitor logs and admin activity:

   Watch for suspicious logins, unexpected admin actions, and further profile changes. Keep copies of logs for investigation.

6. Apply perimeter protections (WAF / virtual patching):

   Consider using a properly configured Web Application Firewall (WAF) to block obvious exploit patterns at the perimeter while you plan a code-level fix. Tuned WAF rules can reduce immediate risk for stored XSS attacks — see example rules below. Test rules in monitor mode first to avoid disrupting legitimate traffic.

Perimeter mitigation — example WAF rules and guidance

While code fixes are the only complete remediation, virtual patching via a WAF can buy time. Example ModSecurity-style rules and regex patterns are provided as starting points; tune them to your traffic and test in staging before enforce mode.

Block script tags and attribute injections in POST fields

# Block obvious script tag injections in form inputs
SecRule REQUEST_METHOD "POST" "chain,deny,status:403,log,msg:'Possible stored XSS in profile photo URL - blocking request'"
  SecRule ARGS_NAMES|ARGS "(profile|profile_picture|picture|user_meta|avatar|photo)" "chain"
    SecRule ARGS "(?i)(<\s*script|onerror\s*=|onload\s*=|javascript:|data:text/html|data:image/svg\+xml|

(?i)^\s*(javascript:|data:|vbscript:)

# Allow only http(s) URLs that end in common image extensions
SecRule ARGS:get_avatar|ARGS:profile_picture|ARGS:avatar "(?i)^(https?://[^\s'\"<>]+(\.jpg|\.jpeg|\.png|\.gif|\.webp)(\?.*)?)$" "allow,log,msg:'Valid avatar URL'"
SecRule ARGS:get_avatar|ARGS:profile_picture|ARGS:avatar "." "deny,log,msg:'Avatar URL invalid or potentially harmful'"

# Notes:
# - Start rules in monitoring mode to capture false positives.
# - Target only profile update endpoints to avoid broader disruptions.
# - Ensure legitimate Gravatar or non-image workflows are allowed if required.

SELECT user_id, meta_key, meta_value
FROM wp_usermeta
WHERE meta_key LIKE '%avatar%' OR meta_key LIKE '%picture%' OR meta_key LIKE '%profile%';

SELECT * FROM wp_usermeta WHERE meta_value LIKE '%<script%';

# Example replaces '<script' occurrences in usermeta with an empty string (test in staging)
wp db query "UPDATE wp_usermeta SET meta_value = REPLACE(meta_value, '<script', '') WHERE meta_value LIKE '%<script%';"

$avatar_url = get_user_meta( $user_id, 'profile_picture', true );
$avatar_url = esc_url( $avatar_url );
echo '<img src="' . esc_attr( $avatar_url ) . '" alt="' . esc_attr( $user_display_name ) . '" >';

SecRule ARGS_NAMES|ARGS "(avatar|profile_picture|picture|photo)" "chain,deny,status:403,log,msg:'Block avatar field javascript: scheme'"
  SecRule ARGS "(?i)^\s*javascript:"

SecRule REQUEST_BODY "(?i)(%3Cscript%3E|%3C%2Fscript%3E|%3Csvg|%3Conerror%3D|%3Cimg%20src%3D)" "deny,log,status:403,msg:'Encoded script tag in POST body detected'"

SecRule ARGS|get_avatar|ARGS:profile_picture "(?i)^(https?://[^\s'\"<>]+(\.jpg|\.jpeg|\.png|\.gif|\.webp)(\?.*)?)$" "id:1001,allow"
SecRule ARGS|get_avatar|ARGS:profile_picture "." "id:1002,deny,log,msg:'Avatar URL denied — only http/https image URLs allowed'"