# CVE-2026-61774: NVIDIA Megatron Bridge unsafe deserialization

Source: https://junglewise.ai/threats/cve-2026-61774-nvidia-megatron-bridge-unsafe-deserialization  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-01. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-61774 · Severity: high · CVSS 7.8 · Published 2026-09-01

NVIDIA Megatron Bridge is a deep learning framework component used for distributed training of large language models. A deserialization vulnerability allows an attacker to execute arbitrary code, tamper with model data, or steal sensitive training information if they can control serialized data fed to the system.

Technologies: [Nvidia Megatron-Bridge](https://junglewise.ai/threats/technologies/megatron-bridge), [Nvidia Nemo Megatron Bridge](https://junglewise.ai/threats/technologies/nemo-megatron-bridge). Vendors: [Nvidia](https://junglewise.ai/threats/vendors/nvidia).

## Quick answers

**Is CVE-2026-61774 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-61774 being exploited in the wild.

**How severe is CVE-2026-61774?** High severity, with a CVSS score of 7.8, published 1 September 2026.

**Which products and versions are affected?** NVIDIA Megatron Bridge.

**Is there a fix for CVE-2026-61774?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-61774 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-61774?** Check whether you run Nvidia Megatron-Bridge or Nvidia Nemo Megatron Bridge. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability exists in NVIDIA Megatron Bridge's deserialization logic, which unsafely processes untrusted serialized data. An attacker who can supply malicious serialized objects (e.g., via compromised model checkpoints, training data inputs, or network communication) can trigger code execution with the privileges of the Megatron process. No authentication is typically required if the attacker controls data ingestion points. The vulnerability enables arbitrary code execution, data tampering, and information disclosure. Patches are expected from NVIDIA.

## Affected products

- NVIDIA Megatron Bridge

## Timeline

- 2026-09-01: disclosed

## References

- [https://github.com/NVIDIA/product-security/tree/main/2026/5868](https://github.com/NVIDIA/product-security/tree/main/2026/5868)
- [https://www.cve.org/CVERecord?id=CVE-2026-61774](https://www.cve.org/CVERecord?id=CVE-2026-61774)

## Related threats

- [NVIDIA Megatron Bridge deserialization vulnerability](https://junglewise.ai/threats/cve-2026-61779-nvidia-megatron-bridge-deserialization-vulnerability)
- [NVIDIA Megatron Bridge deserialization of untrusted data](https://junglewise.ai/threats/cve-2026-61778-nvidia-megatron-bridge-deserialization-of-untrusted-data)
- [NVIDIA Megatron Bridge unsafe deserialization](https://junglewise.ai/threats/cve-2026-61777-nvidia-megatron-bridge-unsafe-deserialization)
- [NVIDIA Megatron Bridge deserialization of untrusted data](https://junglewise.ai/threats/cve-2026-61776-nvidia-megatron-bridge-deserialization-of-untrusted-data)
- [NVIDIA Megatron Bridge unsafe deserialization](https://junglewise.ai/threats/cve-2026-61775-nvidia-megatron-bridge-unsafe-deserialization)