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": "2026-09-01T16:17:08.360Z",
  "pubdate": "2026-09-01T16:17:08.360Z",
  "executiveSummary": "The NVIDIA Megatron Bridge is affected by a critical deserialization vulnerability involving the processing of untrusted data.\nThis flaw allows a remote or local attacker to manipulate serialized objects, leading to arbitrary code execution, unauthorized data modification, or the disclosure of sensitive system information.\nThe vulnerability originates from the improper handling of untrusted input during the deserialization process, which lacks adequate validation or integrity checks.\nSuccessful exploitation grants an attacker the ability to execute arbitrary commands within the security context of the application process.\nThe risk is categorized as high due to the potential for full system compromise, data breach, and loss of confidentiality, integrity, and availability.\nImpacted systems include instances where the Megatron Bridge component is deployed and exposed to untrusted input sources.\nExploitation generally requires the attacker to submit a maliciously crafted object to a vulnerable endpoint or interface that consumes serialized data.",
  "technicalDetails": "The root cause of this vulnerability lies in the insecure implementation of deserialization routines within the NVIDIA Megatron Bridge. Deserialization is the process of converting a stream of bytes back into a complex object; when an application performs this operation on untrusted input without sufficient validation, it becomes susceptible to object injection attacks.\nAn attacker can exploit this by crafting a serialized payload containing malicious object graphs. When the Megatron Bridge deserializes this input, it recreates the object in memory. If the application environment contains 'gadget chains'—classes available in the classpath that perform dangerous actions (such as invoking reflection, filesystem operations, or network connections) during or immediately after the instantiation process—the attacker can achieve code execution.\nThe attack flow follows a structured trajectory: First, the attacker identifies an interface or service within the Megatron Bridge that accepts serialized data as input. Second, the attacker generates a malicious payload using specialized tools that leverage existing gadget chains present in the application's dependencies or core libraries. Third, the attacker transmits this payload to the target endpoint. Upon processing the input, the deserialization mechanism inadvertently executes the logic contained within the malicious object, allowing the attacker to bypass access controls, execute arbitrary system commands, or manipulate application memory states.\nBecause the deserialization occurs before the application can enforce authorization checks, the payload is executed with the same privileges as the service performing the deserialization. This enables persistent unauthorized access, data exfiltration, or lateral movement within the network, depending on the service's privileges. The vulnerability remains critical as it circumvents standard input filtering, as the threat is embedded within the structure of the serialized data itself, rather than simple input strings that might be caught by traditional Web Application Firewalls (WAFs).\nFurther post-exploitation impact includes the potential for privilege escalation if the Megatron Bridge is running with elevated system or service-level permissions. By hijacking the object instantiation flow, the attacker can redirect execution to memory segments that reveal sensitive configuration data, credentials, or transient runtime information, leading to comprehensive information disclosure."
}