Description

NVIDIA Megatron Bridge contains a vulnerability where an attacker could cause a deserialization of untrusted data. A successful exploit of this vulnerability might lead to code execution, data tampering, and information disclosure.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "7.8",
  "pubDate": "2026-09-01T16:17:09.980Z",
  "pubdate": "2026-09-01T16:17:09.980Z",
  "executiveSummary": "The NVIDIA Megatron Bridge is affected by a critical deserialization vulnerability involving the processing of untrusted input data. This security flaw stems from the insecure handling of serialized objects, allowing an unauthenticated or remote attacker to inject malicious data structures into the application stream.\nThe exploitation of this vulnerability can lead to arbitrary code execution, unauthorized data tampering, and the potential exposure of sensitive internal information. By manipulating serialized payloads, an attacker may bypass standard security controls to execute arbitrary logic within the context of the affected process.\nThis vulnerability poses a significant risk to the integrity, availability, and confidentiality of the host environment. The impact is severe, as successful exploitation may grant an attacker complete control over the vulnerable service. Organizations utilizing affected versions of NVIDIA Megatron Bridge should prioritize defensive measures to mitigate the risk of unauthorized access and system compromise.",
  "technicalDetails": "The vulnerability resides in the deserialization mechanism of the NVIDIA Megatron Bridge, which fails to properly validate or sanitize incoming serialized objects. In environments where the system automatically deserializes data from untrusted sources without implementing strict class white-listing or integrity verification, the application becomes susceptible to object injection attacks.\nThe root cause is the reliance on insecure deserialization primitives that permit the instantiation of arbitrary classes or the triggering of 'gadget chains'—sequences of existing code within the application or its dependencies that can be repurposed to perform malicious operations. When the bridge processes a specifically crafted malicious serialized object, it deserializes the payload, which can lead to unintended execution paths.\nThe attack flow typically begins with an attacker identifying an input vector that transmits serialized data to the NVIDIA Megatron Bridge. The attacker crafts a malicious payload containing serialized object graphs designed to manipulate the application's runtime state or trigger specific methods during the reconstruction process. Upon receipt, the application's deserialization function processes this payload. If the payload contains a weaponized gadget chain, the application may execute arbitrary system commands or perform unauthorized memory operations.\nThe technical impact includes the potential for remote code execution, whereby the attacker achieves full compromise of the underlying process. Additionally, the ability to tamper with deserialized data allows an attacker to alter business logic, escalate privileges, or corrupt the state of the application. Information disclosure may occur if the attacker forces the deserialization process to return sensitive object attributes or state information that should remain private to the application.\nBecause the vulnerability involves the fundamental way the application reconstructs data structures, it does not necessarily require prior authentication if the vulnerable endpoint is exposed to the network. Exploitation success is dependent on the presence of suitable gadgets within the application's classpath or loaded libraries, but given the nature of complex framework dependencies, this is often highly achievable for a motivated threat actor.\nThe vulnerability manifests during the object reconstruction phase of data handling. By exploiting the inherent trust placed in serialized metadata, the attacker shifts the execution flow away from expected programmatic behavior into an adversary-controlled execution context, effectively subverting the security posture of the NVIDIA Megatron Bridge."
}