Stack-based buffer overflow in Apache HTTP Server - CVE-2026-63292
Published: October 1, 2026
Vulnerability identifier: #VU153105
CSH Severity: High
CVSS v4: 9.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-63292
CWE-ID: CWE-121
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service or potentially execute arbitrary code.
The vulnerability exists due to a stack-based buffer overflow in mod_vhost_alias when processing an HTTP request with a Host header exceeding 8192 bytes. A remote attacker can send a specially crafted HTTP request to cause a denial of service or potentially execute arbitrary code.
Exploitation requires VirtualDocumentRoot to use a hostname format specifier and LimitRequestFieldSize to be raised above its default value.
Affected software
Apache HTTP Server
How to mitigate CVE-2026-63292
Install security update from vendor's website.
Apache HTTP Server - update to 2.4.69