Severity by source
AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Local delivery of a malicious artifact with no auth (AV:L, PR:N) but a victim must load it (UI:R); deserialization yields full code execution, so C/I/A all High.
Primary rating from Vendor (nvidia).
CVSS VectorVendor: nvidia
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Lifecycle Timeline
2DescriptionCVE.org
NVIDIA Megatron Bridge for Linux contains a vulnerability where an attacker could cause deserialization of untrusted data. A successful exploit of this vulnerability might lead to code execution, escalation of privileges, data tampering, and information disclosure.
Articles & Coverage 1
AnalysisAI
Arbitrary code execution and privilege escalation in NVIDIA Megatron Bridge on Linux arises from unsafe deserialization of untrusted data, allowing a local attacker who convinces a user to load a malicious serialized object to run code, tamper with data, and disclose information. NVIDIA (the reporting vendor) rates it 7.8 (High); the CVSS vector requires local access and user interaction, so exploitation is not remote-unauthenticated. There is no public exploit identified at time of analysis and it is not listed in CISA KEV.
Technical ContextAI
Megatron Bridge is NVIDIA's open-source library used in large-language-model and deep-learning training pipelines to bridge and convert model checkpoints/state between frameworks (e.g., Megatron-Core and Hugging Face formats). The affected component is identified by CPE cpe:2.3:a:nvidia:megatron-bridge:*:*:*:*:*:*:*:*. The root cause is CWE-502 (Deserialization of Untrusted Data): the library reconstructs objects from serialized input (commonly Python pickle-based checkpoint or config formats in the ML ecosystem) without validating that the data is trustworthy, so a crafted payload can trigger object instantiation that executes attacker-controlled code during the load step.
RemediationAI
Upgrade NVIDIA Megatron Bridge to the fixed release identified in NVIDIA's advisory at https://github.com/NVIDIA/product-security/tree/main/2026/5841 - a patch is available per the vendor advisory, but the exact fixed version is not stated in the available data and must be read from that advisory. Until patched, treat all model checkpoints, configuration files, and serialized artifacts as untrusted: only load checkpoints from sources you control or have cryptographically verified, and avoid loading third-party or downloaded models on privileged training hosts (trade-off: blocks convenient reuse of public model artifacts). Where the workflow allows, restrict who can supply files to the load path and run conversion/loading jobs under a low-privilege, sandboxed account or container to contain the impact of a malicious deserialization (trade-off: added operational overhead), and prefer safe serialization formats (e.g., safetensors) over pickle-based formats where the tooling supports it.
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Same weakness CWE-502 – Deserialization of Untrusted Data
View allSame technique Deserialization
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External POC / Exploit Code
Leaving vuln.today
EUVD-2026-41044
GHSA-wh7f-f43p-5q6v