Description

IBM i 7.6, 7.5, 7.4, and 7.3 could allow a remote authenticated attacker to execute arbitrary code due to a buffer overflow.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.8",
  "pubDate": "2026-08-13T20:17:19.097Z",
  "pubdate": "2026-08-13T20:17:19.097Z",
  "executiveSummary": "A buffer overflow vulnerability has been identified in IBM i versions 7.6, 7.5, 7.4, and 7.3, posing significant security risks to enterprise environments utilizing these operating systems.\nThis vulnerability is classified as a memory corruption flaw stemming from improper bounds checking during data processing within the affected software components.\nSuccessful exploitation of this security defect allows a remote authenticated attacker to execute arbitrary code with the privileges of the vulnerable process or service.\nThe primary impact of this vulnerability includes complete system compromise, unauthorized execution of administrative commands, data alteration, and potential disruption of critical business operations.\nThe attacker capabilities require prior authentication to the targeted system, indicating that the threat actor must possess valid user credentials to initiate the attack vector.\nExploitation requirements dictate that the attacker must interact with the vulnerable component over the network while supplying a maliciously crafted payload designed to overflow the designated memory buffer.\nRisk implications are severe, as unauthorized arbitrary code execution undermines the integrity, confidentiality, and availability of the underlying IBM i operating system and associated workloads.\nOrganizations operating the specified versions must prioritize remediation efforts to prevent malicious actors from leveraging authenticated access to escalate privileges or execute unauthorized system commands.",
  "technicalDetails": "The vulnerability resides in internal memory handling routines within IBM i 7.6, 7.5, 7.4, and 7.3, where input data is copied into fixed-length memory buffers without adequate bounds checking.\nThe root cause is programmatic failure to validate the size of incoming data streams against the allocated capacity of the destination buffer during specific request processing routines.\nWhen an authenticated attacker transmits an oversized input payload to the vulnerable application component, the excess data overflows the boundary of the allocated stack or heap buffer, overwriting adjacent memory regions.\nThe attack flow begins with the threat actor authenticating to the IBM i system using valid credentials, establishing a valid session or connection to the target service.\nFollowing authentication, the attacker crafts a malicious request containing a carefully constructed payload designed to overwrite critical execution pointers, such as return addresses or function pointers, stored on the stack.\nUpon processing the oversized input, the application fails to truncate the data, resulting in memory corruption as the execution flow is redirected to attacker-supplied shellcode or arbitrary instructions embedded within the payload.\nBecause the execution occurs within the context of the vulnerable service, the payload inherits the privileges associated with that process, potentially granting the attacker elevated capabilities depending on the service configuration.\nPost-exploitation impact includes the ability to execute arbitrary code, install persistent backdoors, manipulate system configurations, access sensitive system data, and perform lateral movement across the enterprise network.\nThe vulnerability affects network-exposed services running on IBM i 7.6, 7.5, 7.4, and 7.3, requiring remote access capabilities combined with authenticated session establishment.\nNo specific privilege requirements beyond standard remote authentication are inherently mandated to trigger the memory corruption condition, provided the user can interact with the vulnerable parsing routine."
}