PHP 5.6.40 was released on January 10, 2019, as the final security release for the PHP 5.6 lifecycle [1]. This version marked the official End-of-Life (EOL) for the PHP 5.x branch [1]. Since that date, the PHP development team has not provided official security patches, bug fixes, or updates for this version [1].
Use tools to scan your codebase for deprecated functions.
The core issues found in PHP 5.6.40 typically reside within its built-in extensions—specifically standard data handling tools like Multibyte String ( mbstring ), the GD Graphics Library , XML-RPC , and the PHAR stream wrapper. Because PHP 5 memory management lacks many modern guardrails found in PHP 8.x, attackers exploit these extensions to corrupt memory and force system level actions.
I can provide tailored code snippets or specific refactoring steps to help you safely transition away from PHP 5.6. Share public link php version 5640 vulnerabilities link
function, potentially allowing an unauthenticated remote attacker to compromise the system. Risks of Using PHP 5.6.40 in 2026
After 5.6.40 was released, many critical CVEs were discovered that affect the 5.6 branch but were for 5.6.x. Examples include:
Using PHP 5.6.40 in 2026 is considered high-risk. Automated scanners frequently identify hundreds of known vulnerabilities in environments running this version. Snyk - Vulnerability report for Docker php:5.6.40-apache Use tools to scan your codebase for deprecated functions
This link provides JSON and XML feeds, official CVSS scores, and impact metrics.
: Tiny cracks in how the server handled data, potentially allowing an attacker to crash the system.
Here are the authoritative links to search for PHP 5.6.40 vulnerabilities: I can provide tailored code snippets or specific
This public link is valid for 7 days and shares a thread, including any personal information you added. This link or copies made by others cannot be deleted. If you share with third parties, their policies apply. Can’t copy the link right now. Try again later.
Fixed CVE-2019-9023 , which addressed multiple memory corruption and buffer overflows in multibyte regex functions.
Fixed CVE-2019-9021 , a heap buffer overflow found in the phar_detect_phar_fname_ext function.
PHP version 5.6.40, released in January 2019, was the final security update for the PHP 5.6 branch and is now end-of-life (EOL). While it addressed several critical issues, it remains vulnerable to newer exploits discovered after its support ended.
Step 2: Utilize Extended Lifecycle Support (If Upgrading Immediately is Impossible)