CVE-2025-47277

By default, Red Hat products are configured to restrict vLLM nodes to an isolated network. However, this vulnerability could become relevant if customers change the specific configurations, and therefore, Red Hat products are affected.

This vulnerability is classified as Moderate rather than Critical because its exploitability and impact are constrained by specific deployment contexts and assumptions about network trust boundaries. While the use of pickle.loads on untrusted input typically leads to remote code execution (RCE), the vulnerable PyNcclPipe interface is not intended to be exposed to the internet or untrusted networks, it is designed for use within a secured, internal cluster environment as explicitly documented by vLLM. Successful exploitation requires an attacker to have direct network access to a misconfigured or poorly segmented system where the KV cache transfer service is bound to a public interface. Additionally, the vulnerable code path exists only in a niche configuration (V0 engine with PyNcclPipe), further reducing its exposure. Therefore, while the flaw does introduce RCE risk in misconfigured setups, the combination of non-default exposure, clear documentation, and limited applicability justifies a reduced impact.