Critical Apache HTTP Server Vulnerability Puts Millions of Servers at Risk of RCE

Severity

High

Detail

A critical vulnerability has been identified in Apache HTTP Server, one of the most widely used web servers globally. The flaw, tracked as CVE-2026-23918, could allow attackers to execute malicious code remotely on affected systems. The vulnerability is caused by a “double free” memory corruption issue in the handling of HTTP/2 requests. When a specially crafted “early reset” frame is processed, the server incorrectly frees the same memory twice, leading to unstable memory behavior.

In less severe cases, this flaw may cause the server to crash, resulting in a Denial-of-Service (DoS) condition. However, in more advanced scenarios, attackers can exploit the issue to achieve Remote Code Execution (RCE), enabling them to run arbitrary commands on the target system.

Given the widespread use of Apache across enterprise and public-facing infrastructure, this vulnerability significantly expands the potential attack surface and may impact millions of servers worldwide. Successful exploitation could lead to full system compromise, data exfiltration, or deployment of malware and ransomware.

CVE ID	Summary	CVSS Score
CVE-2026-23918	Double free memory corruption in Apache HTTP Server HTTP/2 processing allows potential remote code execution.	8.8 (High)

Affected Products

The vulnerability impacts the following product and version:

Apache HTTP Server version 2.4.66 (when HTTP/2 module is enabled)

Recommendation

Organizations and administrators are strongly advised to take the following actions immediately:

Upgrade Apache HTTP Server to version 2.4.67
Monitor server logs for unusual HTTP/2 activity, unexpected resets, or unexplained crashes
Temporarily disable HTTP/2 support if immediate patching is not feasible
Implement defense-in-depth measures such as web application firewalls (WAFs), intrusion detection systems, and strict access controls

Failure to apply the necessary updates may result in remote code execution, system compromise, and potential data breaches.

Source
https://cyberpress.org/critical-apache-http-server-vulnerability-2/