CVE-2026-28780
Apache HTTP Server: buffer overflow in mod_proxy_ajp via ajp_msg_check_header()
- State
- Published
- Severity
- 9.8 Critical
- Published
- May 5, 2026
- Updated
- Sep 14, 2026
- Reserved
- Mar 3, 2026
Description
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 9.8 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H | CISA-ADP |
| 3.1 | 8.1 High | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H | redhat-SADP |
Weaknesses
Affected Products
| Product | Versions |
|---|---|
Apache HTTP ServerApache Software Foundation |
|
References
- https://httpd.apache.org/security/vulnerabilities_24.htmlvendor-advisory
- http://www.openwall.com/lists/oss-security/2026/05/05/9
- https://access.redhat.com/security/cve/CVE-2026-28780vdb-entry
- RHBZ#2466913issue-tracking
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-28780.json
- https://access.redhat.com/errata/RHSA-2026:27200vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:47046vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:21433vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:22140vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:36846vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:36831vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:36373vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:67152vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:66323vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:62165vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:21391vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:27201vendor-advisory
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.