Description

IBM AIX 7.2, and 7.3 and IBM PowerVM VIOS 4.1 could allow a remote attacker to cause a denial of service due to unbounded recursion.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.5",
  "pubDate": "2026-08-19T20:17:02.930Z",
  "pubdate": "2026-08-19T20:17:02.930Z",
  "executiveSummary": "This vulnerability involves a denial of service security flaw residing within IBM AIX 7.2, IBM AIX 7.3, and IBM PowerVM VIOS 4.1. The underlying weakness stems from improper handling of recursive operations, which leads directly to unbounded recursion within the affected software components. A remote attacker can exploit this condition to exhaust system resources, ultimately causing the targeted operating system or virtual I/O server to crash or become entirely unresponsive.\nThe risk implications are significant for enterprise environments relying on these virtualization and operating system platforms, as a successful exploitation results in an immediate denial of service, disrupting critical workloads and virtual machine management operations. The vulnerability requires network access to the target system, allowing remote threat actors to trigger the recursion flaw without necessarily requiring prior authentication or elevated privileges, depending on the specific network service exposed. Exploitation relies on sending specially crafted network traffic or data inputs designed to initiate and perpetuate the unbounded recursive calls within the vulnerable parsing or processing routines.",
  "technicalDetails": "The vulnerability is characterized by a lack of proper depth checking or recursion termination conditions within vulnerable code paths of IBM AIX 7.2, IBM AIX 7.3, and IBM PowerVM VIOS 4.1. When the affected component processes specific inputs or protocol messages, it initiates recursive function calls to parse or evaluate the data structure. Because the application fails to validate the nesting depth or limit the recursive iterations, a meticulously crafted input payload forces the function to continually call itself.\nThe step-by-step attack flow begins when a remote attacker transmits a malicious payload across the network to an exposed service or listening daemon running on the vulnerable IBM AIX or PowerVM VIOS instance. Upon receipt, the vulnerable component attempts to process the incoming data structure. As the parser navigates through the deeply nested or recursive elements, the software executes successive function calls, rapidly consuming available stack memory frame allocations. \nAs the unbounded recursion continues unabated, the process exhausts the call stack limits, triggering a stack overflow condition. This memory exhaustion corrupts adjacent memory regions or instantly halts the execution thread, leading to a catastrophic kernel panic, system daemon termination, or complete node crash. The affected versions include IBM AIX 7.2 and 7.3, alongside IBM PowerVM VIOS 4.1. Network exposure of vulnerable management or communication daemons facilitates remote exploit delivery. While authentication and privilege requirements depend on the specific vector exposed, the vulnerability fundamentally enables remote attackers to disrupt system availability through resource exhaustion payloads."
}