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Home / Blog / wordpress 4.5.3
Security Advisory

WordPress 4.5.3: 32 Critical Vulnerabilities Explained

📅 June 07, 2026 ·⏱ 5 min read ·🔒 SiteRecipe Security Team
88 websites still running wordpress 4.5.3  → View full list
32
Total
2
Critical
10
High
20
Medium

WordPress 4.5.3 is an older version of the world's most popular website platform, released several years ago. Unfortunately, this version contains 32 known security vulnerabilities that put your website at serious risk, including 2 critical-level flaws that attackers actively exploit. If your site still runs WordPress 4.5.3, you need to take immediate action to protect your data, your visitors, and your business.

These vulnerabilities range from allowing attackers to upload malicious files to stealing sensitive information through SQL injection attacks. With 88 websites still using this outdated version, hackers know exactly what to look for. This guide will help you understand these threats and show you exactly how to fix them.

What is Wordpress 4.5.3?

WordPress 4.5.3 is a version of WordPress released in 2016—nearly a decade ago. Think of WordPress as the engine that powers your website, handling everything from displaying your content to managing user accounts and plugins. Version 4.5.3 introduced several features and improvements, but like all software, security experts have discovered vulnerabilities (weaknesses) in the code that bad actors can exploit.

Security vulnerabilities are essentially holes or flaws in software that attackers can use to break into your system. In WordPress 4.5.3, these holes allow hackers to upload dangerous files, steal data, or take complete control of your website. Because this version is so old, it's no longer receiving security updates from WordPress developers, meaning any new vulnerabilities discovered won't be fixed.

Key Vulnerabilities in Wordpress 4.5.3

32 CVEs found. The most critical are explained below.

CRITICAL CVE-2020-35945 9.9/10 · CVSS v3.1 ⏱ Immediate
Divi Theme Allows Uploading Dangerous Files

The Divi Builder plugin has a security weakness that lets people with contributor access or higher upload any type of file to your website, including dangerous executable files. The security check only happens in the browser, which is easy to bypass.

Impact: An attacker could upload malicious code that takes control of your entire website, steals customer data, or uses your site to attack others.

↗ View on NVD
CRITICAL CVE-2025-54677 9.1/10 · CVSS v3.1 ⏱ Immediate
vcita Booking Plugin Allows Dangerous File Uploads

The vcita Online Booking plugin has a flaw that allows uploading malicious files to your website. Anyone with plugin access could exploit this to gain control of your site.

Impact: Attackers could install backdoors, steal customer information, or hijack your website completely.

↗ View on NVD
HIGH CVE-2021-24631 8.8/10 · CVSS v3.1 ⏱ Immediate
Unlimited PopUps Plugin Database Injection Flaw

The Unlimited PopUps plugin doesn't properly filter user input before using it in database queries. Editors and higher-level users can exploit this to access or modify your entire database.

Impact: Sensitive data could be exposed, customer information could be stolen or deleted, and your site's functionality could be disrupted.

↗ View on NVD
HIGH CVE-2023-0875 8.8/10 · CVSS v3.1 ⏱ Immediate
WP Meta SEO Plugin Database Security Flaw

The WP Meta SEO plugin doesn't properly protect database queries from malicious input. Even low-level users (subscribers) can exploit this vulnerability to access your database.

Impact: Private information stored in your database could be exposed to unauthorized users without leaving obvious traces.

↗ View on NVD
HIGH CVE-2024-31210 7.6/10 · CVSS v3.1 ⏱ Within 7 days
Plugin Upload Security Bypass

WordPress has a flaw in its plugin upload feature that allows uploading files that aren't actually plugins. If your host requests FTP credentials during installation, attackers could exploit this.

Impact: An attacker with admin access could upload malicious files disguised as plugins, potentially taking over your website.

↗ View on NVD
HIGH CVE-2016-5832 7.5/10 · CVSS v3.0 ⏱ Within 30 days
WordPress Customizer Redirection Bypass

An older vulnerability in WordPress versions before 4.5.3 allows attackers to bypass security redirects in the customizer tool through specific methods.

Impact: Attackers could redirect users away from your site or access restricted areas they shouldn't be able to reach.

↗ View on NVD

Additional Vulnerabilities (26 more)

Showing first 10 of 26. View all on NVD ↗

CVE IDSeverityScore PublishedDescription
CVE-2016-5835 HIGH 7.5 2016-06-29 WordPress before 4.5.3 allows remote attackers to obtain sensitive revision-history information by leveraging the ability to read a post, related to wp-admin/includes/ajax-actions…
CVE-2016-5836 HIGH 7.5 2016-06-29 The oEmbed protocol implementation in WordPress before 4.5.3 allows remote attackers to cause a denial of service via unspecified vectors.
CVE-2016-5837 HIGH 7.5 2016-06-29 WordPress before 4.5.3 allows remote attackers to bypass intended access restrictions and remove a category attribute from a post via unspecified vectors.
CVE-2016-5838 HIGH 7.5 2016-06-29 WordPress before 4.5.3 allows remote attackers to bypass intended password-change restrictions by leveraging knowledge of a cookie.
CVE-2016-5839 HIGH 7.5 2016-06-29 WordPress before 4.5.3 allows remote attackers to bypass the sanitize_file_name protection mechanism via unspecified vectors.
CVE-2016-6896 HIGH 7.1 2017-01-18 Directory traversal vulnerability in the wp_ajax_update_plugin function in wp-admin/includes/ajax-actions.php in WordPress 4.5.3 allows remote authenticated users to cause a denia…
CVE-2025-54676 MEDIUM 6.5 2025-08-14 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') vulnerability in vcita Online Booking & Scheduling Calendar for WordPress by vcita meeting-sch…
CVE-2023-6561 MEDIUM 6.4 2024-01-11 The Featured Image from URL (FIFU) plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the featured image alt text in all versions up to, and including, 4.5.3 du…
CVE-2024-2255 MEDIUM 6.4 2024-03-20 The Essential Blocks – Page Builder Gutenberg Blocks, Patterns & Templates plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's widgets in all versio…
CVE-2025-4611 MEDIUM 6.4 2025-05-21 The Slim SEO – Fast & Automated WordPress SEO Plugin plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's slim_seo_breadcrumbs shortcode in all versi…
Full Report Available

All 32 CVEs with AI explanations + fix guide

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How to Fix These Vulnerabilities

Conclusion

Running WordPress 4.5.3 is like leaving your front door unlocked in a neighborhood full of burglars. The 32 vulnerabilities in this version, especially the 2 critical-level flaws, make your website an easy target for hackers who can steal data, inject malware, or destroy your site entirely. Updating to the latest WordPress version takes less than an hour and eliminates the vast majority of these risks.

Don't wait for a breach to happen. Use SiteRecipe.com's automated security scanning tools to identify vulnerabilities in your WordPress installation right now. Our platform monitors your site 24/7, alerts you to security issues, and provides step-by-step guidance to fix them. Visit SiteRecipe.com today for a free security audit and sleep better knowing your website is protected.

Frequently Asked Questions

Is WordPress 4.5.3 still supported with security updates?
No. WordPress 4.5.3 was released in 2016 and stopped receiving security updates years ago. WordPress only actively supports the current version and the two previous major releases. Any vulnerabilities discovered in 4.5.3 will never be patched by the WordPress team, leaving your site permanently exposed.
Can I safely update from WordPress 4.5.3 to the latest version?
Yes, WordPress updates are designed to be backward compatible. However, you should always back up your site first and test the update on a staging environment if possible. Most sites update without issues, but your specific plugins or custom code might need adjustments. SiteRecipe.com can help identify potential compatibility issues before you update.
What's the biggest risk if I don't update from WordPress 4.5.3?
The two critical vulnerabilities allow attackers to upload malicious PHP files to your server, giving them complete control over your website. They could steal customer data, inject malware into pages, use your server to attack other sites, or hold your data for ransom. Even one successful attack can cost thousands in recovery fees and reputation damage.
How long does it take to update WordPress from 4.5.3?
The WordPress core update typically takes 5-15 minutes depending on your site size. Updating plugins and themes might take another 15-30 minutes. The entire process, including a backup, usually takes under an hour. Compare that to the days or weeks it could take to recover from a security breach.

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DISCLAIMER: This report is based on publicly available CVE data from the National Vulnerability Database (NVD) maintained by NIST. Detection of a technology version does not confirm active exploitation on any specific website. For informational purposes only. SiteRecipe is not responsible for actions taken based on this report. Always consult a qualified security professional.

Source: nvd.nist.gov · Published: June 07, 2026 · SiteRecipe.com