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": "2026-09-01T16:17:12.923Z",
  "pubdate": "2026-09-01T16:17:12.923Z",
  "executiveSummary": "The NVIDIA Megatron Bridge is affected by an insecure deserialization vulnerability, which poses a critical security risk to the integrity, availability, and confidentiality of the host environment.\nThis vulnerability stems from the improper handling of untrusted data during the deserialization process, allowing an attacker to inject malicious serialized objects into the application pipeline.\nSuccessful exploitation of this flaw can lead to arbitrary code execution (ACE) with the privileges of the application process, potentially resulting in unauthorized data tampering and the disclosure of sensitive information.\nThe vulnerability affects the NVIDIA Megatron Bridge, and exploitation does not require advanced cryptographic bypasses if the deserialization endpoint is exposed to an untrusted input source.\nGiven the potential for complete system compromise, organizations should treat this vulnerability with high priority, focusing on strict input validation and the implementation of secure object handling practices to prevent malicious object instantiation.",
  "technicalDetails": "The vulnerability resides within the deserialization logic of the NVIDIA Megatron Bridge, which fails to adequately validate the stream of data before reconstructing objects in memory.\nInsecure deserialization occurs when an application receives a serialized object from an external, untrusted source and attempts to deserialize it without implementing sufficient integrity checks or type constraints.\nThe root cause of this issue is the use of unsafe deserialization libraries or patterns that permit the instantiation of arbitrary classes present in the application's classpath. By crafting a malicious serialized payload, an attacker can influence the state of the application's memory.\nThe attack flow begins when an attacker identifies an endpoint or interface within the NVIDIA Megatron Bridge that accepts serialized objects. The attacker then constructs a 'gadget chain'—a series of existing classes within the application or its dependencies that, when invoked during the deserialization process, perform unintended actions.\nWhen the Megatron Bridge process receives and processes the payload, the underlying deserialization mechanism triggers the chain of methods, often involving 'magic methods' like readObject, which are automatically invoked during reconstruction.\nIf successfully triggered, the payload execution typically results in remote code execution, as the attacker can force the application to execute system commands, load arbitrary libraries, or manipulate internal object state to bypass security controls.\nThis vulnerability is particularly dangerous because the malicious payload is executed within the context of the application's runtime. If the Megatron Bridge is running with elevated system privileges, the impact of the resulting code execution is magnified, potentially allowing the attacker to establish persistence or move laterally within the infrastructure.\nData tampering occurs if the deserialized objects are used to define critical application configuration or security tokens. By injecting specific object types, an attacker could potentially overwrite critical application parameters, modify sensitive data structures, or elevate their privileges to perform unauthorized administrative actions.\nThe disclosure of sensitive information is also a potential outcome, as the attacker could leverage the deserialization gadget chain to extract memory contents, read sensitive configuration files, or intercept internal communications, leading to a compromise of confidentiality."
}