The Apache HTTP Server's mod_proxy_ajp module contains a heap-based buffer overflow vulnerability (CVE-2026-28780) that can lead to arbitrary code execution. This vulnerability is one among several related issues in mod_proxy_ajp and mod_authn_socache, including heap-based buffer over-reads and NULL pointer dereferences. The Red Hat Product Security team has released an important security advisory (RHSA-2026:21433) providing updated httpd packages for Red Hat Enterprise Linux 10 and its extended update support variants. The advisory details fixes for CVE-2026-28780 and related CVEs (CVE-2026-33007, CVE-2026-33857, CVE-2026-34032, CVE-2026-34059). The vulnerability has a CVSS v3.1 base score of 9.8, reflecting critical impact with network attack vector and no required privileges or user interaction. The advisory includes links to updated packages and instructions for applying the update.

Successful exploitation of CVE-2026-28780 allows an attacker to execute arbitrary code remotely on affected systems running Apache HTTP Server with the vulnerable mod_proxy_ajp module. The vulnerability has a critical CVSS score of 9.8, indicating high impact on confidentiality, integrity, and availability. Other related vulnerabilities in the same advisory include memory disclosure, out-of-bounds reads, and denial of service via NULL pointer dereference. These combined issues can lead to system compromise or service disruption if not remediated.

Red Hat has released updated httpd packages that address CVE-2026-28780 and related vulnerabilities as part of advisory RHSA-2026:21433. Users running Red Hat Enterprise Linux 10 and its variants should apply the security update promptly to mitigate these issues. Detailed instructions and updated packages are available at https://access.redhat.com/articles/11258. Since this is not a cloud service, remediation requires manual patching by system administrators. No indication of known exploits in the wild has been reported at this time.