Critical Apache HTTP/2 Flaw Could Let Unauthenticated Attackers Execute Code Remotely

A critical flaw in Apache HTTP Server's HTTP/2 module could allow unauthenticated attackers to remotely execute code and potentially take control of affected server processes. Tracked as CVE-2026-119618, the vulnerability affects Apache HTTP Server 2.4.55 through 2.4.70 when HTTP/2 is enabled and is fixed in version 2.4.71. The Hacker News reports: The vendor's assessment, published yesterday, also says "public research has demonstrated a reliable exploit" against a server in its default configuration with mod_http2 enabled. It does not name or link that research. Security company Wiz said later that day that no exploit was available and that no exploitation in the wild had been reported.

HTTP/2 runs only where the Protocols directive turns it on, as the module documentation explains. The directive uses h2 for HTTP/2 over TLS and h2c for HTTP/2 over plain TCP. It can be set for the whole server or for a single virtual host, so admins should check the server-wide setting and every virtual host.

Standalone builds of the module, released on GitHub as mod_h2, are affected from version 2.0.8 through 2.0.42. Admins who run the Apache HTTP Server project's own releases should move to version 2.4.71, the fixed release named in its security advisory. That release also fixes a crash in mod_md, rated important, and a one-byte overwrite of stack memory in mod_vhost_alias, rated low.