Description

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

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-08-13T20:17:17.840Z",
  "pubdate": "2026-08-13T20:17:17.840Z",
  "executiveSummary": "An out-of-bounds write vulnerability has been identified in IBM i versions 7.6, 7.5, 7.4, and 7.3. This vulnerability allows a local attacker to execute arbitrary code on the underlying operating system.\nThe security flaw stems from improper boundary checking within memory management operations, which can be leveraged to corrupt adjacent memory regions and achieve arbitrary code execution.\nSuccessful exploitation of this vulnerability requires local access to the target system. An authenticated local attacker with malicious intent can manipulate inputs or system interfaces to trigger the out-of-bounds write condition.\nThe potential impact of this security issue is severe, as successful code execution grants the attacker the ability to compromise the integrity, confidentiality, and availability of the affected IBM i environment. Depending on the privileges held during execution, this could lead to full system compromise.\nOrganizations utilizing the affected IBM i versions face significant risk until appropriate remediation measures are applied. Immediate focus should be placed on identifying applicable vendor-supplied patches and adhering to strict local access control principles to minimize the potential attack surface.",
  "technicalDetails": "The vulnerability is classified as an out-of-bounds write, occurring when software writes data past the end, or before the beginning, of the intended buffer or memory structure. This memory corruption flaw is typically rooted in unsafe arithmetic operations involving size calculations or a lack of rigorous input validation prior to memory write operations.\nIn the context of IBM i 7.6, 7.5, 7.4, and 7.3, the vulnerable component fails to properly validate the length of data being written into memory buffers. When a local attacker provides specially crafted input or interacts with vulnerable system interfaces, the write operation exceeds the allocated boundaries of the target buffer.\nThe attack flow requires the adversary to have local access to the vulnerable IBM i system. The attacker initiates a sequence of actions that invokes the vulnerable function or system component. During execution, the crafted input triggers the out-of-bounds condition, overwriting adjacent memory addresses, which may contain critical execution control data, function pointers, or application state variables.\nBy meticulously engineering the payload injected via the out-of-bounds write, the attacker can hijack the execution flow of the application or operating system kernel. This allows the redirection of execution to malicious shellcode or arbitrary instructions supplied by the attacker.\nBecause the vulnerability is triggered locally, network exposure is not a primary vector unless combined with another remote access flaw. However, privilege and authentication requirements depend on the specific entry point abused by the local attacker, though standard exploitation scenarios frequently aim to elevate local privileges or execute code within a privileged context.\nPost-exploitation impact includes the execution of arbitrary commands with the privileges of the compromised process or system context, potentially granting the attacker complete administrative control over the IBM i operating environment, persistent access, and the ability to manipulate sensitive system data."
}