Heap-based buffer overflow in Apache HTTP Server - CVE-2026-28780
Published: May 4, 2026
Vulnerability identifier: #VU129548
CSH Severity: High
CVSSv4.0: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-28780
CWE-ID: CWE-122
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerable software:
Apache HTTP Server
Apache HTTP Server
Software vendor:
Apache Foundation
Apache Foundation
Description
The vulnerability allows a remote attacker to cause a denial of service or potentially execute arbitrary code.
The vulnerability exists due to a heap-based buffer overflow in mod_proxy_ajp ajp_msg_check_header() when processing AJP messages from a backend server. A remote attacker can send a specially crafted AJP message to cause a denial of service or potentially execute arbitrary code.
The malicious AJP server can cause 4 attacker-controlled bytes to be written past the end of a heap-based buffer.
Remediation
Install security update from vendor's website.