Code execution via AJP header validation overflow
Published May 5, 2026 · Updated May 5, 2026
Heap-based buffer overflow in Apache HTTP Server through 2.4.66 allows remote attackers to corrupt heap memory through a malicious AJP server. In ajp_msg_check_header(), validation of a crafted AJP message writes four attacker-controlled bytes beyond the allocated heap buffer. Exploitation requires mod_proxy_ajp to connect to an attacker-controlled AJP server; the corruption enables code execution or a service crash.
Summary
What happened
Heap-based buffer overflow in Apache HTTP Server through 2.4.66 allows remote attackers to corrupt heap memory through a malicious AJP server. In ajp_msg_check_header(), validation of a crafted AJP message writes four attacker-controlled bytes beyond the allocated heap buffer. Exploitation requires mod_proxy_ajp to connect to an attacker-controlled AJP server; the corruption enables code execution or a service crash.
The record
- CVE
- CVE-2026-28780
- Published
- May 5, 2026
- Updated
- May 5, 2026
- Vendor
- The Apache Software Foundation
- Product
- Apache HTTP Server
- Classifications
- CWE-122, CWE-787, T1210
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 5, 2026CVE publishedPublication date reported by the CVE source.
- May 5, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
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- Affected versionversion=0 <=2.4.66
What conditions does exploitation require?
What is affected?
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
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Technologies
Your stack
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Your stack
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