Description

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

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "5.3",
  "pubDate": "2026-09-04T17:16:54.630Z",
  "pubdate": "2026-09-04T17:16:54.630Z",
  "executiveSummary": "A buffer overflow vulnerability exists within IBM i versions 7.3, 7.4, 7.5, and 7.6, which can be leveraged by remote, unauthenticated attackers to cause a denial of service (DoS) condition.\nThe vulnerability stems from improper boundary checking during data processing, allowing an attacker to supply specially crafted inputs that exceed memory buffer allocations.\nSuccessful exploitation results in the destabilization of system processes or services, leading to a complete service disruption or system hang, effectively rendering the impacted IBM i system unavailable to legitimate users.\nThe risk is categorized as high due to the potential for remote exploitation without the requirement for prior authentication, necessitating immediate administrative attention to mitigate potential service availability impact.",
  "technicalDetails": "The vulnerability manifests as a stack-based or heap-based buffer overflow within the affected IBM i environment. This occurs when the system fails to perform sufficient validation on the length of input data provided through specific network-facing interfaces or protocols before copying the data into a fixed-length memory buffer.\nIn a typical attack flow, an unauthorized remote actor transmits a malicious payload designed to exceed the predefined bounds of a destination buffer. By overwriting adjacent memory segments, the attacker can corrupt the execution state of the process, overwriting return addresses, function pointers, or critical control data structures.\nThe memory corruption leads to an unhandled exception or an invalid state within the IBM i kernel or associated middleware services. Because the process cannot gracefully handle the memory violation, it triggers a crash or forces the service into an infinite loop or deadlock condition, resulting in a denial of service (DoS).\nAffected products include IBM i versions 7.3, 7.4, 7.5, and 7.6. The exploitation process does not require high-privileged access or user interaction, as the vulnerable component is reachable via the network. Attackers can automate the delivery of malformed packets to trigger the overflow, causing widespread service disruption across the infrastructure.\nThe impact of the vulnerability is significant because the crash of core IBM i processes may necessitate a manual system reboot or service restart to recover, causing downtime for critical business operations and application services relying on the platform."
}