CVE-2026-28780 Apache HTTP Server: buffer overflow in mod_proxy_ajp via ajp_msg_check_header()
A heap-based buffer overflow in Apache HTTP Server's mod_proxy_ajp allows attackers to execute code or cause denial of service via malicious AJP responses.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-28780?
CVE-2026-28780 is a critical memory corruption vulnerability in Apache Http Server, published on 5 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Which versions are affected by CVE-2026-28780?
1 open source package ship an affected version, including apache. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
apache Bitnami | All versions | 2.4.67 |
Products include Apache Http Server.
How do I fix CVE-2026-28780?
Upgrade apache to 2.4.67 or later.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-28780 being exploited?
There is no known exploitation of CVE-2026-28780 in the wild and no public exploit code.
Other vulnerabilities in Apache Http Server
Sources
Also known as ALPINE-CVE-2026-28780, BELL-CVE-2026-28780, BIT-apache-2026-28780, CLSA-2026-1778847162, CLSA-2026-1779124722, CLSA-2026-1779129626 and 5 more.