CVE-2026-28780

CRITICAL severity · CVSS 9.8 · CWE-122

9.8CVSS CRITICAL

Summary

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.

Impact & exploitability

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

Confidentiality impactHigh

Integrity impactHigh

Availability impactHigh

Exploit probability (EPSS)0%

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products we track (1)

Apache HTTP Server

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

Additional information

NVD record
https://httpd.apache.org/security/vulnerabilities_24.htmlAdvisory
http://www.openwall.com/lists/oss-security/2026/05/05/9Advisory