5640 Vulnerabilities Link | Php Version

Attackers can leverage an out-of-bounds read error in the base64 parsing code of XML-RPC to view unallocated memory areas. 4. PHAR Extension Buffer Over-Read

Known as CVE-2019-9021 , a heap-based buffer over-read happens during the filename expansion phase within phar_detect_phar_fname_ext .

PHP 5.6.40 Vulnerabilities: Why You Must Upgrade in 2026 As of May 2026, running PHP 5.6.40 is not just risky—it is a critical security vulnerability. While PHP 5.6 was a stable and widely adopted version in its prime, the final release (5.6.40) arrived on January 10, 2019, and official security support ended long ago. php version 5640 vulnerabilities link

Inadequate input validation inside the xmlrpc_decode function allows attackers to pass hostile payloads. This forces out-of-bounds reads or read-after-free states, risking system compromise.

Deploy the application to a staging environment running the target PHP version to perform comprehensive regression testing. Attackers can leverage an out-of-bounds read error in

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:

1. Regular Expression Memory Corruption (Mbstring Extension) in some cases

You can find more information on these vulnerabilities and their fixes on the official PHP website:

https://nvd.nist.gov/vuln/search/results?form_type=Basic&results_type=overview&query=PHP+5.6.40&search_type=all

Unpatched memory management issues in the PHP core can lead to service disruptions or, in some cases, remote code execution.