Apache HTTP Server: buffer overflow in mod_proxy_ajp via ajp_msg_check_header()
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.
02 / AFFECTED SOFTWARE
Affected packages
1 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
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.
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.
05 / REFERENCES
Further evidence
- http://www.openwall.com/lists/oss-security/2026/05/05/9
- https://access.redhat.com/errata/RHSA-2026:21391
- https://access.redhat.com/errata/RHSA-2026:21433
- https://access.redhat.com/errata/RHSA-2026:22140
- https://access.redhat.com/errata/RHSA-2026:27200
- https://access.redhat.com/errata/RHSA-2026:27201
- https://access.redhat.com/errata/RHSA-2026:36373
- https://access.redhat.com/errata/RHSA-2026:36831
- https://access.redhat.com/errata/RHSA-2026:36846
- https://access.redhat.com/errata/RHSA-2026:47046
- https://access.redhat.com/security/cve/CVE-2026-28780
- https://bugzilla.redhat.com/show_bug.cgi?id=2466913
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/28xxx/CVE-2026-28780.json
- https://httpd.apache.org/security/vulnerabilities_24.html
- https://nvd.nist.gov/vuln/detail/CVE-2026-28780
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28780.json