CVE-2026-28780 — Apache HTTP Server: buffer overflow in mod_proxy_ajp via ajp_msg_check_header()

Description (CNA)

Heap-based Buffer Overflow vulnerability in mod_proxy_ajp of Apache HTTP Server. If mod_proxy_ajp connects to a malicious AJP server this AJP server can send a malicious AJP message back to mod_proxy_ajp and cause it to write 4 attacker controlled bytes after the end of a heap based buffer. This issue affects Apache HTTP Server: through 2.4.66. Users are recommended to upgrade to version 2.4.67, which fixes the issue.

Affected (CNA)

Vendor / product	Versions
Apache Software Foundation / Apache HTTP Server	affected 0 through 2.4.66

CWE

CWE-122

References

https://httpd.apache.org/security/vulnerabilities_24.html

ADP enrichment

CVE

No English description supplied.

http://www.openwall.com/lists/oss-security/2026/05/05/9

CISA-ADP

No English description supplied.

No references supplied.

redhat-SADP

A flaw was found in mod_proxy_ajp of Apache HTTP Server. This heap-based buffer overflow vulnerability allows a remote attacker, by connecting to a malicious AJP (Apache JServ Protocol) server, to send a specially crafted message. This message can cause mod_proxy_ajp to write attacker-controlled data beyond a heap-based buffer, potentially leading to arbitrary code execution or a denial of service.