Apache 2.4.18 Vulnerabilities Jun 2026

In the lifecycle of web server infrastructure, few components are as critical—and yet often neglected—as the HTTP server itself. Apache HTTP Server, the backbone of the internet for decades, has gone through numerous iterations. Version 2.4.18, released in December 2015, represents a specific snapshot in the server's history.

Version 2.4.18 relied on older logic regarding session handling. In subsequent versions (specifically around 2.4.25), fixes were applied regarding how mod_session handles cookies. While less "flashy" than injection attacks, session handling vulnerabilities can lead to session hijacking or privilege escalation if the session storage is manipulated. apache 2.4.18 vulnerabilities

However, being released in late 2015 means it predates several major discoveries in web security, including the HTTP Desync attacks and various path traversal vulnerabilities. While 2.4.18 fixed issues present in the 2.4.17 branch, it simultaneously opened the door for new vulnerabilities that were discovered in subsequent months and years. In the lifecycle of web server infrastructure, few

One of the most notable vulnerabilities present in the initial 2.4.18 release was discovered in 2016. Version 2

While the initial "Zero-Day" hype in 2021 (CVE-2021-41773) regarding path traversal largely targeted misconfigured servers (requiring Require all granted on the root directory), the vulnerability highlighted a weakness in how Apache normalizes paths.

– mod_http2 improper error handling (affects 2.4.18–2.4.23)