{"id":6711,"date":"2026-05-05T22:18:11","date_gmt":"2026-05-05T22:18:11","guid":{"rendered":"https:\/\/delimiter.online\/blog\/apache-http-2-vulnerability\/"},"modified":"2026-05-05T22:18:11","modified_gmt":"2026-05-05T22:18:11","slug":"apache-http-2-vulnerability","status":"publish","type":"post","link":"https:\/\/delimiter.online\/blog\/apache-http-2-vulnerability\/","title":{"rendered":"Apache HTTP\/2 flaw CVE-2026-23918 carries DoS and RCE risk"},"content":{"rendered":"

The Apache Software Foundation has released security updates for the Apache HTTP Server<\/a>, addressing multiple vulnerabilities including a critical flaw in the HTTP\/2 protocol handling that could enable both denial of service attacks and potential remote code execution<\/a>.<\/p>\n

The vulnerability, formally tracked as CVE-2026-23918, carries a CVSS severity score of 8.8. The Apache team described the issue as a case of double free and possible remote code execution within the servers HTTP\/2 connection management.<\/p>\n

A double free error occurs when software attempts to release a memory allocation more than once, corrupting the memory management structures. In this context, successful exploitation could allow an attacker to crash the server or, in more severe scenarios, execute arbitrary code on the affected system.<\/p>\n

Scope of the vulnerability<\/h2>\n

The advisory applies to Apache HTTP Server versions 2.4.0 through 2.4.62. Users running these versions are affected by the flaw, which stems from improper handling of certain HTTP\/2 frames during connection teardown.<\/p>\n

Attackers could potentially exploit this weakness by sending specially crafted HTTP\/2 requests to a vulnerable server, triggering the memory corruption condition. While the primary impact is denial of service, the possibility of remote code execution elevates the severity rating significantly.<\/p>\n

Remote code execution would allow an attacker to run arbitrary commands on the server, potentially leading to data theft, system compromise, or use of the server as a pivot point for further attacks within a network.<\/p>\n

Additional fixes in the update<\/h2>\n

Beyond CVE-2026-23918, the security release addresses several other vulnerabilities of varying severity. These include issues related to request smuggling, information disclosure, and additional denial of service vectors.<\/p>\n

Request smuggling vulnerabilities can allow an attacker to interfere with the way a server processes sequences of HTTP requests, potentially bypassing security controls or gaining unauthorized access to sensitive data.<\/p>\n

The update also resolves problems with the mod_proxy module, which handles proxied connections, and the mod_rewrite module, used for URL manipulation. Specific details on these additional fixes are available in the official Apache HTTP Server change log.<\/p>\n

Recommended actions for administrators<\/h2>\n

System administrators running Apache HTTP Server are strongly advised to upgrade to version 2.4.63 or later as soon as possible. The update is available for download from the official Apache HTTP Server website and through most operating system package managers.<\/p>\n

For organizations unable to apply the update immediately, temporary mitigation measures should be considered. These may include disabling HTTP\/2 support on the server if the protocol is not required for operations, implementing web application firewall rules to filter suspicious HTTP\/2 traffic, and closely monitoring server logs for signs of attempted exploitation.<\/p>\n

Administrators should also review their server configurations for any additional hardening measures, such as limiting connection rates and ensuring proper memory limits are configured.<\/p>\n

Background on HTTP\/2 vulnerabilities<\/h2>\n

HTTP\/2, the second major version of the Hypertext Transfer Protocol, introduced significant performance improvements over its predecessor, HTTP\/1.1, including multiplexed streams, header compression, and server push capabilities.<\/p>\n

However, the complexity of the protocol has led to several security vulnerabilities in various implementations over the years. This latest flaw in the Apache implementation adds to a growing list of issues that have required patches across multiple web server platforms.<\/p>\n

The Apache HTTP Server remains one of the most widely used web server software packages globally, powering a significant portion of websites and web applications. The broad deployment base makes timely patching critical for overall internet security.<\/p>\n

Organizations using Apache in production environments should prioritize testing and deploying this update within their standard patch management cycles. Given the severity rating and the potential for remote code execution, a faster than normal deployment cadence is warranted.<\/p>\n

Security researchers and the Apache community will continue to monitor for any proof of concept exploits or active attacks targeting CVE-2026-23918 in the coming weeks.<\/p>\n

Source: GeekWire<\/p>\n","protected":false},"excerpt":{"rendered":"

The Apache Software Foundation has released security updates for the Apache HTTP Server, addressing multiple vulnerabilities including a critical flaw in the HTTP\/2 protocol handling that could enable both denial of service attacks and potential remote code execution. The vulnerability, formally tracked as CVE-2026-23918, carries a CVSS severity score of 8.8. The Apache team described […]<\/p>\n","protected":false},"author":1,"featured_media":6712,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[505],"tags":[7872,7873,7874,7875,953],"class_list":["post-6711","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-security","tag-apache-http-server","tag-cve-2026-23918","tag-denial-of-service","tag-http-2-vulnerability","tag-remote-code-execution"],"_links":{"self":[{"href":"https:\/\/delimiter.online\/blog\/wp-json\/wp\/v2\/posts\/6711","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/delimiter.online\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/delimiter.online\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/delimiter.online\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/delimiter.online\/blog\/wp-json\/wp\/v2\/comments?post=6711"}],"version-history":[{"count":0,"href":"https:\/\/delimiter.online\/blog\/wp-json\/wp\/v2\/posts\/6711\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/delimiter.online\/blog\/wp-json\/wp\/v2\/media\/6712"}],"wp:attachment":[{"href":"https:\/\/delimiter.online\/blog\/wp-json\/wp\/v2\/media?parent=6711"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/delimiter.online\/blog\/wp-json\/wp\/v2\/categories?post=6711"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/delimiter.online\/blog\/wp-json\/wp\/v2\/tags?post=6711"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}