Description

Deserialization of untrusted data in Microsoft High Performance Computing (HPC) Pack allows an unauthorized attacker to execute code over a network.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "9.8",
  "pubDate": "2026-08-11T17:18:06.287Z",
  "pubdate": "2026-08-11T17:18:06.287Z",
  "executiveSummary": "A critical vulnerability involving the deserialization of untrusted data has been identified in Microsoft High Performance Computing (HPC) Pack. This security flaw enables an unauthorized remote attacker to achieve arbitrary code execution over a network without requiring prior authentication. The vulnerability impacts systems running vulnerable versions of Microsoft HPC Pack, introducing severe risk implications including complete system compromise, unauthorized access to sensitive computational clusters, and potential lateral movement within enterprise network environments. Exploitation requires the attacker to transmit a maliciously crafted serialized payload to vulnerable network services exposed by the affected product, which then improperly processes and instantiates the untrusted data. The lack of adequate type validation and sanitization during the deserialization process allows malicious objects to execute arbitrary instructions within the context of the service account. Organizations deploying Microsoft HPC Pack face significant exposure if network perimeters are not adequately hardened or if patches are not applied, as successful exploitation bypasses standard security controls and grants attackers persistent control over affected nodes.",
  "technicalDetails": "The vulnerability stems from insecure deserialization mechanics implemented within Microsoft HPC Pack components responsible for handling inter-node communication and administrative tasks over the network. Insecure deserialization occurs when untrusted user-supplied data is processed by the application without proper validation, type checking, or filtering, allowing an attacker to manipulate the serialized data stream to instantiate arbitrary classes and invoke dangerous methods during the object creation lifecycle.\nThe attack vector relies on network exposure where vulnerable endpoints accept serialized objects over specific protocols utilized by the HPC infrastructure. An unauthorized attacker initiates the attack flow by constructing a malicious payload containing specially craftedgadget chains—pre-existing sequences of method calls within the application libraries or underlying runtime framework—that execute arbitrary system commands when the object graph is deserialized by the receiving component.\nUpon transmitting the malicious payload across the network to the target Microsoft HPC Pack service, the vulnerable component reads the incoming stream and attempts to reconstruct the objects. During this phase, the execution flow is hijacked as the runtime processes the malicious gadget chain. This triggers unauthorized function execution with the privileges of the service running the affected Microsoft HPC Pack component, which often operates with elevated system or administrative permissions.\nThe root cause is rooted in the lack of robust type filtering mechanisms, such as custom serialization binders or whitelist-based type validation, which permits the deserialization of dangerous types. Post-exploitation impact includes full remote code execution, installation of persistent backdoors, data exfiltration from compute nodes, and potential pivoting to adjacent systems within the high-performance computing cluster network environment."
}