Cyber Resilience

CVE-2026-28780

CriticalUpdated

Published: 05 May 2026

Published
05 May 2026
Modified
30 June 2026
KEV Added
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Patch
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CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0132 67.5th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-28780 is a critical-severity Heap-based Buffer Overflow (CWE-122) vulnerability in Apache Http Server. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 32.5% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

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…

more

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.

CWE(s)
CWE-122CWE-787

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
Why these techniques?

Heap buffer overflow in Apache mod_proxy_ajp allows RCE when proxy connects to attacker-controlled AJP backend, directly enabling exploitation of public-facing web server or remote services.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

Affected Assets

apache
http server
≤ 2.4.67

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SI-16 Memory Protection
addresses: CWE-787

Out-of-bounds writes that corrupt control flow or inject shellcode are rendered non-executable by the same memory protections.

References