Description

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote authenticated attacker to cause a denial of service and obtain sensitive information due to an out-of-bounds read.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.4",
  "pubDate": "2026-08-19T21:16:54.143Z",
  "pubdate": "2026-08-19T21:16:54.143Z",
  "executiveSummary": "An out-of-bounds read vulnerability has been identified in IBM i versions 7.3, 7.4, 7.5, and 7.6. This security flaw introduces significant risk to organizational data integrity and system availability. The vulnerability allows a remote authenticated attacker to trigger memory boundary violations, resulting in a denial of service condition and the unauthorized disclosure of sensitive information.\nThe exploitation of this vulnerability requires prior authentication, indicating that the attacker must possess valid credentials within the target environment. Successful exploitation leverages memory management flaws to read outside allocated buffer boundaries, potentially exposing sensitive system memory contents such as configuration data, credentials, or internal operational structures. Furthermore, repeated or malformed read requests can destabilize the affected services, leading to application crashes or complete denial of service for legitimate users.\nGiven the enterprise nature of IBM i platforms, the potential impact includes compromised confidentiality and availability of critical business workloads. Organizations utilizing the affected software versions must prioritize security updates and apply relevant vendor-supplied patches or workarounds as soon as they become available to mitigate potential exploitation risks.",
  "technicalDetails": "The vulnerability stems from an out-of-bounds read flaw residing within the memory handling routines of IBM i 7.3, 7.4, 7.5, and 7.6. An out-of-bounds read occurs when software reads data from a memory buffer past the end of the allocated structure, typically due to insufficient bounds checking on input parameters or pointer arithmetic errors.\nThe attack vector is network-exposed, allowing a remote authenticated attacker to interact with vulnerable system components. Although the attack requires authentication, a malicious actor who has obtained standard user privileges can exploit this weakness to interact with the underlying memory management interface. By supplying specially crafted inputs or requests, the attacker forces the processing engine to read memory locations outside the designated boundaries of the intended buffer.\nThe attack flow proceeds as follows: First, the authenticated attacker establishes a network connection to the vulnerable service on the IBM i system. Second, the attacker transmits a meticulously constructed request containing invalid length or offset parameters designed to bypass validation checks. Third, the vulnerable component processes the request and executes memory read operations past the intended buffer limits. Fourth, the memory contents retrieved from adjacent regions are either returned to the attacker in response payloads, leading to sensitive information disclosure, or cause an exception and subsequent crash when reading unmapped memory segments, resulting in a denial of service.\nThe payload behavior focuses on extracting arbitrary memory contents or inducing resource exhaustion and application termination. Post-exploitation impact encompasses the exposure of confidential data residing in adjacent memory segments, which may facilitate further attacks, alongside operational disruption caused by service crashes affecting system availability across the affected IBM i environment."
}