Apache HTTP Server 2.4.67 Fixes CVE-2026-23918 HTTP/2 RCE Risk

by Emma Davis
May 5, 2026

Apache HTTP Server 2.4.67 fixes CVE-2026-23918, an HTTP/2 double-free in 2.4.66 that can crash workers and may allow RCE in specific conditions.

Apache HTTP Server 2.4.67 was released on May 4, 2026 to fix CVE-2026-23918, an important HTTP/2 double-free issue affecting Apache httpd 2.4.66. Administrators running 2.4.66 with HTTP/2 enabled should update quickly, because the bug can crash workers and may allow remote code execution in specific runtime conditions.

Cartoon showing an HTTP/2 double-free bug affecting an Apache web server
Two frees for one stream: a bargain no web server asked for.

Why this Apache HTTP/2 bug matters

The Apache advisory describes CVE-2026-23918 as a “double free and possible RCE” issue in HTTP/2 protocol handling and recommends upgrading to Apache HTTP Server 2.4.67. The project credits Bartlomiej Dmitruk of striga.ai and Stanislaw Strzalkowski of isec.pl with reporting the flaw.

The Hacker News reported on May 5 that the denial-of-service path is straightforward when mod_http2 is enabled, while the remote-code-execution path depends on additional memory-layout conditions. That distinction matters: this is not a confirmed mass-exploitation story, but it is a patch-now issue for web servers, hosting stacks, and Docker images that recently moved to httpd 2.4.66.

Site owners should check the installed Apache version, confirm whether HTTP/2 is enabled, and apply the vendor or distribution update that provides 2.4.67. If a production stack cannot be updated immediately, temporarily reducing HTTP/2 exposure may lower risk, but it should not replace the fixed release.

Apache 2.4.67 also fixes several other vulnerabilities, including mod_rewrite privilege escalation, mod_proxy_ajp memory issues, mod_md resource handling, mod_dav_lock crashes, Digest authentication timing behavior, and response-splitting cases. CVE-2026-23918 is the headline because it combines network exposure, HTTP/2 deployment, denial-of-service impact, and possible RCE.

References

  1. Apache HTTP Server Project. “Apache HTTP Server 2.4 vulnerabilities: Fixed in Apache HTTP Server 2.4.67.” https://httpd.apache.org/security/vulnerabilities_24.html
  2. The Hacker News. “Critical Apache HTTP/2 Flaw (CVE-2026-23918) Enables DoS and Potential RCE.” May 5, 2026. https://thehackernews.com/2026/05/critical-apache-http2-flaw-cve-2026.html
  3. CVE Program. “CVE-2026-23918.” https://www.cve.org/CVERecord?id=CVE-2026-23918

About the author

Emma Davis

Content editor and security writer focused on making malware-removal and scam-prevention guides easier to understand. Emma reviews structure, clarity, and source consistency before articles are published.

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