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Home / Blog / PHP 5.4
Security Advisory

PHP 5.4 Security: 129 CVEs Affecting 297 Websites

📅 June 07, 2026 ·⏱ 5 min read ·🔒 SiteRecipe Security Team
297 websites still running PHP 5.4  → View full list
129
Total
18
Critical
55
High
49
Medium
5
Low

PHP 5.4 reached end-of-life in 2014, yet nearly 300 websites still run this outdated version. With 129 documented vulnerabilities—including 18 critical flaws that enable remote code execution—continuing to use PHP 5.4 puts your website at severe risk of compromise, data theft, and complete system takeover.

This comprehensive guide will help you understand the specific threats facing PHP 5.4 installations, identify whether your website is vulnerable, and implement a secure upgrade strategy. Taking action now is not optional; it's essential for protecting your business, users, and reputation.

Don't become another casualty of outdated software. Our security experts have compiled everything you need to modernize your PHP infrastructure and eliminate these critical attack vectors.

What is Php 5.4?

PHP 5.4 is a server-side programming language released in 2012 that powers the backend functionality of websites. If your website runs on PHP, it's the engine that processes user requests, manages databases, handles logins, and delivers dynamic content to visitors. PHP 5.4 was a popular version when released, offering improved performance and new features compared to earlier versions.

However, PHP 5.4 is now ancient by technology standards—officially unsupported since 2014. This means the PHP development team no longer releases security patches or fixes for new vulnerabilities discovered in this version. Every newly discovered threat affecting PHP 5.4 will never be patched, leaving your website permanently exposed to attackers who actively exploit these known weaknesses.

Key Vulnerabilities in Php 5.4

129 CVEs found. The most critical are explained below.

CRITICAL CVE-2012-1823 9.8/10 · CVSS v3.1 ⏱ Immediate
Remote Code Execution via Query String

Attackers can trick your PHP website into running malicious code by sending specially crafted requests through the address bar. This happens because PHP doesn't properly check what's being requested when using CGI mode.

Impact: Hackers could take complete control of your website, steal customer data, install malware, or shut down your site entirely.

↗ View on NVD
CRITICAL CVE-2015-4599 9.8/10 · CVSS v3.0 ⏱ Immediate
SOAP Protocol Information Leak and Crash

If your website uses SOAP (a web service protocol), attackers can send malformed data that exposes sensitive information or crashes your application. This is caused by improper handling of unexpected data types.

Impact: Your website could reveal private information, stop working temporarily, or allow attackers to run malicious code.

↗ View on NVD
CRITICAL CVE-2015-4600 9.8/10 · CVSS v3.0 ⏱ Immediate
SOAP Client Type Confusion Attack

Similar to CVE-2015-4599, this vulnerability affects websites using SOAP services. Attackers exploit confusion about data types to crash your site or potentially execute code.

Impact: Service outages, system crashes, or potential unauthorized code execution on your server.

↗ View on NVD
CRITICAL CVE-2015-4602 9.8/10 · CVSS v3.0 ⏱ Immediate
Incomplete Class Type Confusion Exploit

PHP's way of handling incomplete classes has a flaw where unexpected data types can cause crashes or code execution. Attackers can send malicious input to trigger this vulnerability.

Impact: Your website could crash unexpectedly or allow remote code execution by attackers.

↗ View on NVD
CRITICAL CVE-2015-4603 9.8/10 · CVSS v3.0 ⏱ Immediate
Exception Function Remote Code Execution

A function that displays error traces has a vulnerability where unusual data types can be exploited. Attackers can use this to run their own code on your server.

Impact: Complete compromise of your website and server, allowing attackers to access, modify, or delete all data.

↗ View on NVD
CRITICAL CVE-2015-4642 9.8/10 · CVSS v3.0 ⏱ Immediate
Windows Command Execution Vulnerability

If your website is hosted on Windows servers, attackers can send specially crafted text that tricks PHP into running system commands. This exploits a weakness in how PHP escapes command arguments.

Impact: Attackers could execute operating system commands on your server, giving them full control of your system.

↗ View on NVD

Additional Vulnerabilities (123 more)

Showing first 10 of 123. View all on NVD ↗

CVE IDSeverityScore PublishedDescription
CVE-2015-4643 CRITICAL 9.8 2016-05-16 Integer overflow in the ftp_genlist function in ext/ftp/ftp.c in PHP before 5.4.42, 5.5.x before 5.5.26, and 5.6.x before 5.6.10 allows remote FTP servers to execute arbitrary cod…
CVE-2015-5589 CRITICAL 9.8 2016-05-16 The phar_convert_to_other function in ext/phar/phar_object.c in PHP before 5.4.43, 5.5.x before 5.5.27, and 5.6.x before 5.6.11 does not validate a file pointer before a close ope…
CVE-2015-6834 CRITICAL 9.8 2016-05-16 Multiple use-after-free vulnerabilities in PHP before 5.4.45, 5.5.x before 5.5.29, and 5.6.x before 5.6.13 allow remote attackers to execute arbitrary code via vectors related to …
CVE-2015-6835 CRITICAL 9.8 2016-05-16 The session deserializer in PHP before 5.4.45, 5.5.x before 5.5.29, and 5.6.x before 5.6.13 mishandles multiple php_var_unserialize calls, which allow remote attackers to execute …
CVE-2015-8835 CRITICAL 9.8 2016-05-16 The make_http_soap_request function in ext/soap/php_http.c in PHP before 5.4.44, 5.5.x before 5.5.28, and 5.6.x before 5.6.12 does not properly retrieve keys, which allows remote …
CVE-2015-8876 CRITICAL 9.8 2016-05-22 Zend/zend_exceptions.c in PHP before 5.4.44, 5.5.x before 5.5.28, and 5.6.x before 5.6.12 does not validate certain Exception objects, which allows remote attackers to cause a den…
CVE-2014-9912 CRITICAL 9.8 2017-01-04 The get_icu_disp_value_src_php function in ext/intl/locale/locale_methods.c in PHP before 5.3.29, 5.4.x before 5.4.30, and 5.5.x before 5.5.14 does not properly restrict calls to …
CVE-2013-3214 CRITICAL 9.8 2020-01-28 vtiger CRM 5.4.0 and earlier contain a PHP Code Injection Vulnerability in 'vtigerolservice.php'.
CVE-2020-10806 CRITICAL 9.8 2020-03-22 eZ Publish Kernel before 5.4.14.1, 6.x before 6.13.6.2, and 7.x before 7.5.6.2 and eZ Publish Legacy before 5.4.14.1, 2017 before 2017.12.7.2, and 2019 before 2019.03.4.2 allow re…
CVE-2020-16629 CRITICAL 9.8 2021-02-08 PhpOK 5.4.137 contains a SQL injection vulnerability that can inject an attachment data through SQL, and then call the attachment replacement function through api.php to write a P…
Full Report Available

All 129 CVEs with AI explanations + fix guide

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How to Check If Your Website Is Affected

How to Fix These Vulnerabilities

Conclusion

The 129 vulnerabilities in PHP 5.4—particularly the 18 critical remote code execution flaws—represent an existential threat to your website's security. Attackers actively scan the internet for outdated PHP installations because they know these vulnerabilities will never be patched. Upgrading is not a luxury; it's a fundamental security requirement that protects your data, your users, and your business reputation.

Don't wait for a breach to force your hand. Use SiteRecipe.com's comprehensive security analysis tools to identify all outdated software on your website, create an upgrade roadmap, and track your progress toward a secure infrastructure. Our platform helps thousands of website owners eliminate security debt and sleep better at night knowing their sites are protected. Start your free security audit at SiteRecipe.com today and take control of your website's future.

Frequently Asked Questions

Is PHP 5.4 still safe to use if I'm behind a firewall?
No. A firewall protects network access but does nothing against web-based attacks targeting known PHP 5.4 vulnerabilities. Attackers exploit these flaws through HTTP requests, which firewalls allow by design. Your website's security depends on the software itself being current, not on network defenses.
Will upgrading PHP break my website?
Most modern websites upgrade smoothly to current PHP versions. However, very old custom code may have compatibility issues. This is exactly why we recommend testing in a staging environment first. A qualified developer can identify and fix any problems before affecting your live site.
Why are 297 websites still using PHP 5.4 if it's so dangerous?
Many site owners are unaware of the risks, lack technical expertise to upgrade, or fear breaking their sites. Hosting providers sometimes fail to auto-upgrade older accounts. SiteRecipe.com helps bridge this gap by identifying vulnerabilities and providing clear upgrade guidance anyone can follow.
What's the difference between the critical CVEs listed?
CVE-2012-1823 allows code execution through malformed URLs on CGI installations. CVE-2015-4599 through CVE-2015-4603 enable code execution through 'type confusion' vulnerabilities in PHP's internal functions. CVE-2015-4642 allows OS command execution on Windows servers. All are critical—attackers can fully compromise your server using any of them.
How long does a PHP upgrade typically take?
Simple upgrades on well-maintained sites take 1-2 hours. Complex sites with custom code may need a full day of testing and adjustments. Emergency backup and staging testing add safety but minimal time. Most hosting providers offer assisted upgrades at reasonable cost if you need professional help.

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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