Is CVE-2026-39884 actively exploited?

No active exploitation of CVE-2026-39884 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-39884 be exploited remotely?

Yes. CVE-2026-39884 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-39884?

CVE-2026-39884 has a CVSS score of 8.3 (HIGH).

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HIGH

CVE-2026-39884

CWE-88Published: April 15, 2026· Updated: Apr 17, 2026

8.3

CVSS v3.1

EPSS:0.05%probability of exploitation in 30 daysPercentile:14.0th

Official Description

mcp-server-kubernetes is a Model Context Protocol server for Kubernetes cluster management. Versions 3.4.0 and prior contain an argument injection vulnerability in the port_forward tool in src/tools/port_forward.ts, where a kubectl command is constructed via string concatenation with user-controlled input and then naively split on spaces before being passed to spawn(). Unlike all other tools in the codebase which correctly use array-based argument passing with execFileSync(), port_forward treats every space in user-controlled fields (namespace, resourceType, resourceName, localPort, targetPort) as an argument boundary, allowing an attacker to inject arbitrary kubectl flags. This enables exposure of internal Kubernetes services to the network by injecting --address=0.0.0.0, cross-namespace targeting by injecting additional -n flags, and indirect exploitation via prompt injection against AI agents connected to the MCP server. This issue has been fixed in version 3.5.0.

NVD Source

Technical Analysis

CVE-2026-39884 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), with a CVSS base score of 8.3.