CVE-2026-39884

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Source
https://cve.org/CVERecord?id=CVE-2026-39884
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-39884.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-39884
Aliases
Published
2026-04-14T23:25:59.780Z
Modified
2026-07-15T01:48:56.720577040Z
Severity
  • 8.3 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L CVSS Calculator
Summary
MCP Server Kubernetes has Argument Injection in its port_forward tool via space-splitting
Details

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 portforward tool in src/tools/portforward.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.

Database specific 
{
    "cwe_ids": [
        "CWE-88"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/39xxx/CVE-2026-39884.json",
    "cna_assigner": "GitHub_M"
}
References

Affected packages

Git / github.com/flux159/mcp-server-kubernetes

Affected ranges

Type
GIT
Repo
https://github.com/flux159/mcp-server-kubernetes
Events
Introduced
0 Unknown introduced commit / All previous commits are affected
Fixed
fd93b486d1f90688db968acd87726dc70677f01b
Database specific 
{
    "cpe": "cpe:2.3:a:suyogs:mcp-server-kubernetes:*:*:*:*:*:node.js:*:*",
    "source": [
        "AFFECTED_FIELD",
        "CPE_RANGE",
        "REFERENCES"
    ],
    "extracted_events": [
        {
            "introduced": "0"
        },
        {
            "fixed": "3.5.0"
        }
    ]
}

Affected versions

0.*
0.2.4
0.2.5
0.3.0
0.3.1
0.3.2
0.4.0
1.*
1.0.0
1.0.1
1.1.0
1.2.0
1.3.0
1.3.1
1.3.2
1.4.0
1.5.0
1.6.0
1.6.1
1.6.2
2.*
2.0.0
2.1.0
2.1.1
2.2.0
2.2.1
2.3.0
2.3.1
2.4.0
2.4.1
2.4.2
2.4.3
2.4.4
2.4.5
2.4.6
2.4.7
2.4.9
2.5.0
2.5.1
2.6.0
2.7.0
2.8.0
2.9.0
2.9.1
2.9.2
2.9.3
2.9.4
2.9.5
2.9.6
2.9.7
2.9.8
2.9.9
3.*
3.0.0
3.0.1
3.0.2
3.0.3
3.0.4
3.0.5
3.1.0
3.1.1
3.2.0
3.2.1
3.3.0
3.4.0
v0.*
v0.2.0
v0.2.1
v0.2.2
v0.2.3
v0.2.4
v0.2.5
v0.3.0
v0.3.1
v0.3.2
v0.4.0
v1.*
v1.0.0
v1.0.1
v1.1.0
v1.2.0
v1.3.0
v1.3.1
v1.3.2
v1.4.0
v1.5.0
v1.6.0
v1.6.1
v1.6.2
v2.*
v2.0.0
v2.1.0
v2.1.1
v2.2.0
v2.2.1
v2.3.0
v2.3.1
v2.4.0
v2.4.1
v2.4.2
v2.4.3
v2.4.4
v2.4.5
v2.4.6
v2.4.7
v2.4.8
v2.4.9
v2.5.0
v2.5.1
v2.6.0
v2.7.0
v2.8.0
v2.9.0
v2.9.1
v2.9.2
v2.9.3
v2.9.4
v2.9.5
v2.9.6
v2.9.7
v2.9.8
v2.9.9
v3.*
v3.0.0
v3.0.1
v3.0.2
v3.0.3
v3.0.4
v3.0.5
v3.1.0
v3.1.1
v3.2.0
v3.2.1
v3.2.2
v3.3.0
v3.4.0

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-39884.json"