CVE-2026-8834

Vulnerability

IBM HTTP Server versions 8.5 and 9.0 contain a heap-based buffer overflow vulnerability (CWE-122) in the Administration Server component [1]. The flaw is triggered when a privileged user sends a crafted request to the Administration Server. The affected versions are explicitly listed in the IBM security bulletin [1].

Exploitation

An attacker must be a privileged user authenticated to the Administration Server (requires low privileges) and have network access to the adjacent network (AV:A) [1]. No user interaction is required. The attacker sends a specially crafted request that triggers a heap-based buffer overflow, leading to memory corruption.

Impact

Successful exploitation allows the attacker to execute arbitrary code with the privileges of the HTTP Server process, resulting in full compromise of confidentiality, integrity, and availability (CVSS 8.0, High) [1]. Alternatively, the attacker could cause a denial of service.

Mitigation

IBM has released a security bulletin with fixes for the affected versions [1]. Users should apply the latest fix pack or interim fix as specified in the bulletin. No workarounds are documented. The vulnerability is not listed on CISA's Known Exploited Vulnerabilities (KEV) catalog as of the publication date.