Description

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote authenticated attacker to cause a denial of service due to a stack-based buffer overflow.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "6.5",
  "pubDate": "2026-08-13T20:17:14.663Z",
  "pubdate": "2026-08-13T20:17:14.663Z",
  "executiveSummary": "A stack-based buffer overflow vulnerability exists in IBM i versions 7.6, 7.5, 7.4, and 7.3, which can be exploited by a remote authenticated attacker to cause a denial of service.\nThe vulnerability represents a critical risk to system availability, potentially leading to service disruption or application crashes upon successful exploitation.\nThe flaw specifically requires remote authentication, meaning an adversary must possess valid credentials within the target environment to initiate the attack sequence.\nNo explicit user interaction is mandated by the input description, but the prerequisite of authentication narrows the threat actor profile to internal users, compromised accounts, or attackers leveraging prior access.\nOrganizations operating the affected IBM i versions must prioritize risk mitigation strategies to prevent operational disruption stemming from memory corruption and subsequent denial of service conditions.",
  "technicalDetails": "The vulnerability is classified as a stack-based buffer overflow, stemming from unsafe memory management practices within the affected components of IBM i versions 7.6, 7.5, 7.4, and 7.3.\nA stack-based buffer overflow occurs when an application writes more data to a stack-allocated buffer than it can hold, resulting in the overwriting of adjacent stack memory, which typically includes critical control data such as the saved frame pointer and return address.\nTo initiate the attack flow, a remote authenticated threat actor must leverage their access to interact with the vulnerable service or function within the operating system.\nThe attacker supplies a maliciously crafted payload designed to exceed the boundary constraints of the target input buffer.\nAs the application processes the oversized input without adequate bounds checking, the excess data overflows the designated stack buffer, corrupting the call stack architecture.\nWhen the affected function attempts to return execution control, the corrupted return address points to unintended memory locations, precipitating an immediate segmentation fault, application termination, or system destabilization.\nThe resulting impact is a denial of service condition, disrupting normal operational workflows and potentially requiring administrative intervention to restore service availability.\nPrerequisites for this attack vector include network connectivity to the targeted service and a valid set of authentication credentials, emphasizing the importance of robust identity and access management controls."
}