Hacking alert for websites worldwide... KISA: ‘Security updates are needed’

[Financial News] A serious security vulnerability has been discovered in PHP, a programming language widely used on websites around the world. With concerns that attackers could remotely run malicious code without separate authentication, security authorities at home and abroad have urged users to install urgent updates.
On the 22nd, the Korea Internet & Security Agency (KISA) said that two vulnerabilities had recently been identified in PHP: ‘improper exception handling’ (CVE-2026-109618) and ‘use-after-free’ (CVE-2026-109619).
Improper exception handling is a flaw in which a program fails to properly handle unexpected errors or exceptional situations. Use-after-free is a vulnerability that occurs when memory that has already been freed is referenced again. If exploited in an attack, it can cause a program to malfunction or lead to arbitrary code execution.
The affected versions are PHP 8.2, 8.3, 8.4 and 8.5. Specifically, versions earlier than 8.2.35, 8.3.36, 8.4.27 and 8.5.12, respectively, are affected.
KISA recommended updating each version to the corresponding version or later. It particularly emphasized that PHP 8.1 and earlier, which are no longer receiving official security support, should be upgraded to a supported version.
PHP is a server-side programming language widely used in website development. According to W3Techs, a web technology analytics firm, about 75% of websites worldwide for which the server-side programming language can be identified use PHP. WordPress, a content management system (CMS) used by about 43% of all websites, also runs on PHP.
Foreign cybersecurity authorities have also taken action amid concerns that the vulnerabilities could affect a wide range of websites.
Government agencies in some European countries, including the Netherlands and Finland, have reportedly suspended website operations as a precaution. Cybersecurity authorities in Europe, Japan, Australia and elsewhere are also reported to have recommended the relevant security updates.

[email protected] Choi Hye-rim Reporter