CVE-2026-18858

IBM i 7.3, 7.4, 7.5, and 7.6 could allow an unauthenticated remote attacker to bypass security restrictions due to improper access control. By sending a specially crafted HTTP request to any URL within the Navigator application prior to authentication, a bad actor could exploit this vulnerability to alter server-side session security state.

IBM i versions 7.3, 7.4, 7.5, and 7.6 could allow a remote authenticated attacker to obtain sensitive information or execute arbitrary code on the system due to improper data sanitization by the HTTP Server Administration web application.

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote attacker to execute arbitrary code due to a stack-based buffer overflow.

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote authenticated attacker to escalate privileges due to improper authorization in the handling of high-authority threads.

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote attacker to execute arbitrary code due to an out-of-bounds write.

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote authenticated attacker to execute arbitrary code due to an uncontrolled search path element.

IBM i versions 7.3, 7.4, 7.5, and 7.6 could allow a remote authenticated attacker to bypass security restrictions due to improper enforcement of the ChrootDirectory configuration directive.

IBM i versions 7.3, 7.4, 7.5, and 7.6 could allow a remote authenticated attacker to bypass security restrictions due to improper authentication.

IBM i 7.3, 7.4, 7.5, and 7.6 could allow a remote attacker to perform unauthorized manipulation of distributed transactions due to improper validation of attacker-supplied transaction identifiers.

IBM i versions 7.3, 7.4, 7.5, and 7.6 could allow a local attacker to obtain sensitive information due to missing subtree checks during file handle resolution.