Description

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote attacker to bypass security restrictions due to improper validation of user-controlled addresses.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.9",
  "pubDate": "2026-08-13T21:17:44.700Z",
  "pubdate": "2026-08-13T21:17:44.700Z",
  "executiveSummary": "This vulnerability involves an improper validation flaw concerning user-controlled addresses within IBM i. Specifically, the defect resides in IBM i versions 7.6, 7.5, 7.4, and 7.3, potentially allowing an unauthenticated or remote threat actor to bypass established security restrictions. The primary impact of successful exploitation includes unauthorized access to sensitive system resources or functionality that should otherwise be restricted. Risk implications are severe, as compromising security controls on core operating system components often leads to broader systemic compromise, data exfiltration, or unauthorized privilege escalation depending on the affected subsystem. The attacker capabilities required for this exploit involve network connectivity capable of reaching the vulnerable service and crafting malicious requests that manipulate user-controlled address parameters. Exploitation conditions rely on the presence of the improper validation flaw within the address-handling routines of the affected IBM i releases, requiring no specialized user interaction if the targeted vector is remotely accessible over the network.",
  "technicalDetails": "The technical root cause of this vulnerability stems from the inadequate sanitization, parsing, and validation of user-supplied input that specifies memory or network addresses within specific components of IBM i. When the application or operating system subsystem processes network requests or internal data structures containing user-controlled addresses, it fails to adequately verify whether the specified boundaries or values conform to expected safety constraints. This lack of rigorous input validation allows an attacker to supply maliciously crafted data that points to unintended memory locations, objects, or network destinations.\nRegarding the attack flow, a remote attacker initiates exploitation by constructing a specialized payload designed to target the vulnerable address-handling mechanism. The attacker transmits this payload across the network to the targeted IBM i system utilizing the exposed communication protocol or service interface. Upon receipt, the vulnerable component parses the input without performing sufficient bounds checking or structural validation against the user-controlled addresses supplied within the request.\nBecause the input is incorrectly trusted and processed, the execution flow is manipulated, allowing the caller to bypass authentication checks, access control lists (ACLs), or cryptographic boundaries enforced by the operating system. The vulnerable components involved are core subsystems across IBM i 7.6, 7.5, 7.4, and 7.3 that handle address resolution or resource referencing based on external inputs. Depending on the exact interface targeted, the network exposure may include services listening on standard or proprietary ports exposed by the operating system architecture.\nThe post-exploitation impact includes unauthorized interaction with restricted system functions, potential information disclosure of internal memory structures, or circumvention of administrative controls. Authentication and privilege requirements vary depending on the specific vulnerable vector, but the core flaw inherently undermines the trust model by failing to validate user-controlled addresses prior to authorization decisions."
}