UnratedApache Software Foundation

Advisory [CVE-2026-28780] Apache HTTP Server: buffer overflow in mod_proxy_ajp via ajp_msg_check_header

This security Apache Software Foundation advisory covers CVE-2026-28780 affecting Apache HTTP Server.

CVE-2026-28780 Published May 5, 2026Updated by vendor Jul 28, 2026

CVE-2026-28780

Affected products & platforms

Apache Software FoundationHTTP Server

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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.

Affected versions

Apache HTTP Server through 2.4.66

Official advisory · medium-confidence parse· fetched 2 months ago·verify at source

Fixed versions

2.4.67

Official advisory · medium-confidence parse· fetched 2 months ago·verify at source

Mitigation checklist

Recommended fix / mitigation

Users are recommended to upgrade to version 2.4.67, which fixes the issue.

Official advisory · medium-confidence parse· fetched 2 months ago·verify at source

Sources

Official and corroborating records used to build this advisory.

Official vendor advisoryofficial
Official advisory page fetched and parsed for the summary, affected/fixed versions and remediation guidance it provides.
Apache Software Foundation
CVE.org CNA recordCVE.org
Independent CNA record used for near-real-time discovery and missed-CVE reconciliation. Discovered from the machine-readable feed https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/delta.json; this link opens the CVE.org record for CVE-2026-28780 instead of the raw feed document.
CVE Program

Cross-references

Validate CVE metadata against the authoritative registries.

CVE-2026-28780NVD CVE.org MITRE

Official resources

Apache HTTP Server 2.4 vulnerabilities (official fixed-in table) (target: 2.4.67)
Official documentation
This advisory names 2.4.67 as the first fixed release — official upgrade documentation for Apache HTTP Server 2.4 vulnerabilities (official fixed-in table).
ASF Security — reporting & CVE process
Official documentation
The Apache Software Foundation's official security page: how ASF CVEs are published and where each project's advisories live.
Apache project downloads (fixed releases)
Official documentation
Official ASF download tree — fetch the fixed release named in this advisory from the project's directory.

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