Apache HTTP Server Security Alert: 3 Flaws, One Enables Remote RCE

The Apache Software Foundation has released version Apache HTTP Server 2.4.71, a security update published on November 11, 2026, which addresses three security vulnerabilities, one of which is classified as critical, the second as high risk, and the third as low impact. The most dangerous of these vulnerabilities could allow an attacker to execute arbitrary code remotely (RCE) on the target server, making the installation of the update a matter of utmost importance, especially for infrastructures exposed to the Internet.

The primary vulnerability is identified as CVE-2026-119618 and affects the mod_http2 module responsible for handling HTTP/2 connections. This vulnerability is tied to a race condition during the execution of the assign_headers() function, following improperly asynchronous access to a shared resource.

From a technical standpoint, the issue could lead to heap memory corruption (Heap Corruption), a condition that can be exploited, under certain circumstances, to achieve arbitrary code execution. Affected versions range from Apache HTTP Server 2.4.55 through 2.4.70. The same issue also affects the mod_h2 project releases on GitHub, from version 2.0.8 through 2.0.42.

The vulnerability was discovered thanks to the work of Anthropic OSS Scanner together with researchers Anthony Weems and Simon Scannell of the Google Cloud Vulnerability Research team. The report reached Apache’s security team between October 26 and November 3, 2026.

Regarding the second vulnerability, CVE-2026-106023, it is classified as high risk and affects the module mod_md dedicated to automatic management of digital certificates. This issue involves a NULL Pointer Dereference vulnerability that occurs during the processing of HTTP requests.

The null pointer handling error could cause the server’s child processes to crash, affecting the service availability and opening the door to denial‑of‑service attacks (Denial of Service). Affected versions include those from 2.4.30 through 2.4.70.

Finally, vulnerability CVE-2026-109163 concerns the mod_vhost_alias module and consists of a one‑byte stack buffer overflow. The issue affects versions 2.4.69 and 2.4.70, and has been classified as low impact. This vulnerability was discovered after applying a previous fix for the issue identified as CVE-2026-63292.

All three security vulnerabilities have been fixed in Apache HTTP Server 2.4.71. System administrators should verify installed versions and schedule the update as soon as possible, especially on systems that use HTTP/2 and are directly accessible over the public Internet.

Luigi Zullo

Cybersecurity researcher with experience in vulnerability analysis, cyber risk mitigation, red teaming and ethical hacking, and the protection of complex systems. Specializing in penetration testing and threat intelligence, he helps strengthen the digital resilience of corporate infrastructures and networks.

Areas of Expertise: Penetration Testing, Threat Intelligence, Red Teaming, Vulnerability Assessment, Incident Response