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": "2026-09-01T16:17:08.247Z",
  "pubdate": "2026-09-01T16:17:08.247Z",
  "executiveSummary": "A deserialization vulnerability has been identified within NVIDIA Megatron Bridge, originating from the insecure handling of untrusted data inputs.\nThe vulnerability allows an unauthenticated or authenticated attacker to inject maliciously crafted serialized objects into the application processing pipeline.\nSuccessful exploitation of this flaw can lead to critical security compromises, including arbitrary code execution (ACE) within the context of the application, unauthorized data tampering, and the unauthorized disclosure of sensitive system information.\nThe risk is considered severe due to the potential for full system compromise, depending on the privilege level of the underlying service.\nAttackers do not necessarily require prior system access to initiate the exploit, provided they can reach the vulnerable entry point that triggers the deserialization routine.\nThis issue exposes the infrastructure to significant security risks, necessitating prompt intervention to prevent potential weaponization.",
  "technicalDetails": "The vulnerability exists within the deserialization logic of NVIDIA Megatron Bridge, specifically where the application attempts to reconstruct objects from external or untrusted input streams without performing adequate validation or sanitization.\nThe root cause is the reliance on insecure deserialization functions, which often do not verify the integrity or the class type of the incoming serialized data before instantiation. When an application deserializes a malicious object, it may trigger unintended code paths, such as magic methods (e.g., __wakeup, __destruct, or readObject), which can be abused by an attacker to execute arbitrary instructions.\nThe attack flow begins with the identification of an endpoint or service that accepts serialized data as part of its communication protocol. An attacker constructs a malicious payload containing a gadget chain—a sequence of existing code components within the application's classpath or environment—that, when deserialized, executes an arbitrary command or function.\nOnce the payload is transmitted to the vulnerable NVIDIA Megatron Bridge component, the application's deserialization routine processes the stream. Because the object is reconstituted in the application's memory space, the gadget chain executes with the privileges of the service account running Megatron Bridge.\nThis leads to Remote Code Execution (RCE), where the attacker gains the ability to execute system commands, access files, or pivot through the network. Furthermore, because the attacker can manipulate the state of the objects being deserialized, they can facilitate data tampering by altering application-level business logic, or achieve information disclosure by forcing the application to serialize and transmit internal object states that contain credentials, tokens, or sensitive data.\nThe impact of this vulnerability is significant, as it bypasses traditional security controls that rely on input filtering, focusing instead on the logic of the object reconstruction itself. Post-exploitation, an attacker can maintain persistence, exfiltrate data, or disrupt the availability of the affected system."
}