Apache HTTP Server Patched for Critical RCE Vulnerability (CVE-2026-23918)
The Apache Software Foundation has released an urgent security update to address a severe vulnerability (CVE-2026-23918) in the Apache HTTP Server, which could allow remote code execution (RCE) on affected systems. The flaw, classified as a "double free" memory corruption issue, stems from improper handling of HTTP/2 "early reset" commands, causing the server to free the same memory block twice.
Exploitation of this bug could lead to server crashes (resulting in denial-of-service attacks) or, in worst-case scenarios, enable attackers to execute arbitrary code, gain control of the system, steal data, or deploy ransomware. The vulnerability affects Apache HTTP Server version 2.4.66 with HTTP/2 enabled, posing a significant risk due to the server’s widespread use.
Discovered by researchers Bartłomiej Dmitruk (striga.ai) and Stanisław Strzałkowski (isec.pl), the flaw was privately reported to Apache on December 10, 2025. While a fix was implemented the following day, the official patch was released on May 4, 2026, as part of version 2.4.67. Administrators are advised to update immediately or disable HTTP/2 as a temporary mitigation. Unusual HTTP/2 traffic or server crashes in logs may indicate attempted exploitation.
Source: https://gbhackers.com/apache-http-server-vulnerability-exposes-millions-rce/
Apache Software Foundation TPRM report: https://www.rankiteo.com/company/the-apache-software-foundation
"id": "the1777962299",
"linkid": "the-apache-software-foundation",
"type": "Vulnerability",
"date": "5/2026",
"severity": "100",
"impact": "5",
"explanation": "Attack threatening the organization's existence"{'affected_entities': [{'industry': 'Technology/Internet Infrastructure',
'location': 'Global',
'name': 'Apache HTTP Server users',
'type': 'Software/Server'}],
'attack_vector': "HTTP/2 'early reset' commands",
'data_breach': {'data_exfiltration': 'Potential'},
'date_detected': '2025-12-10',
'date_publicly_disclosed': '2026-05-04',
'date_resolved': '2026-05-04',
'description': 'The Apache Software Foundation has released an urgent '
'security update to address a severe vulnerability '
'(CVE-2026-23918) in the Apache HTTP Server, which could allow '
'remote code execution (RCE) on affected systems. The flaw, '
"classified as a 'double free' memory corruption issue, stems "
"from improper handling of HTTP/2 'early reset' commands, "
'causing the server to free the same memory block twice. '
'Exploitation could lead to server crashes or enable attackers '
'to execute arbitrary code, gain control of the system, steal '
'data, or deploy ransomware.',
'impact': {'data_compromised': 'Potential data theft',
'downtime': 'Server crashes (Denial-of-Service)',
'operational_impact': 'System control, arbitrary code execution, '
'ransomware deployment',
'systems_affected': 'Apache HTTP Server version 2.4.66 with HTTP/2 '
'enabled'},
'investigation_status': 'Resolved',
'post_incident_analysis': {'corrective_actions': 'Patch released in version '
'2.4.67',
'root_causes': "Improper handling of HTTP/2 'early "
"reset' commands leading to double "
'free memory corruption'},
'ransomware': {'data_exfiltration': 'Potential'},
'recommendations': 'Update to Apache HTTP Server version 2.4.67 immediately '
'or disable HTTP/2 as a temporary mitigation.',
'references': [{'source': 'Apache Software Foundation'},
{'source': 'Researchers Bartłomiej Dmitruk (striga.ai) and '
'Stanisław Strzałkowski (isec.pl)'}],
'response': {'communication_strategy': 'Public disclosure and advisory',
'containment_measures': 'Disable HTTP/2 as temporary mitigation',
'enhanced_monitoring': 'Check logs for unusual HTTP/2 traffic or '
'server crashes',
'remediation_measures': 'Update to Apache HTTP Server version '
'2.4.67'},
'stakeholder_advisories': 'Administrators advised to update or disable '
'HTTP/2.',
'title': 'Apache HTTP Server Patched for Critical RCE Vulnerability '
'(CVE-2026-23918)',
'type': 'Remote Code Execution (RCE)',
'vulnerability_exploited': 'CVE-2026-23918 (double free memory corruption)'}