CVE-2026-46519: CWE-863: Incorrect Authorization in Flux159 mcp-server-kubernetes
mcp-server-kubernetes is a Model Context Protocol server for Kubernetes cluster management. Prior to version 3.6.0, mcp-server-kubernetes exposes three environment variables (ALLOW_ONLY_READONLY_TOOLS, ALLOW_ONLY_NON_DESTRUCTIVE_TOOLS, ALLOWED_TOOLS) documented as access controls for restricting which Kubernetes operations are available. These controls are enforced at the tool discovery layer (tools/list) but not at the execution layer (tools/call). Any client that knows a tool name can invoke it directly regardless of the configured restriction mode. The access control was effectively cosmetic. This issue has been patched in version 3.6.0.
AI Analysis
Technical Summary
The vulnerability in mcp-server-kubernetes involves improper enforcement of access controls defined by environment variables ALLOW_ONLY_READONLY_TOOLS, ALLOW_ONLY_NON_DESTRUCTIVE_TOOLS, and ALLOWED_TOOLS. These controls restrict which Kubernetes operations are available, but enforcement occurs only at the tool discovery layer (tools/list) and not at the execution layer (tools/call). Consequently, any client aware of a tool's name can execute it regardless of configured restrictions, effectively bypassing authorization. This flaw is classified as CWE-863 (Incorrect Authorization). The issue was addressed and patched in version 3.6.0 of mcp-server-kubernetes.
Potential Impact
An attacker with at least limited privileges (PR:L) can bypass intended access restrictions and execute potentially destructive Kubernetes operations, leading to high confidentiality, integrity, and availability impacts. This could allow unauthorized modification or disruption of Kubernetes cluster management functions.
Mitigation Recommendations
Upgrade mcp-server-kubernetes to version 3.6.0 or later, where this authorization bypass vulnerability has been fixed. No other official remediation or temporary fixes are documented. Until upgrading, be aware that environment variable-based access controls are ineffective at preventing unauthorized tool execution.
CVE-2026-46519: CWE-863: Incorrect Authorization in Flux159 mcp-server-kubernetes
Description
mcp-server-kubernetes is a Model Context Protocol server for Kubernetes cluster management. Prior to version 3.6.0, mcp-server-kubernetes exposes three environment variables (ALLOW_ONLY_READONLY_TOOLS, ALLOW_ONLY_NON_DESTRUCTIVE_TOOLS, ALLOWED_TOOLS) documented as access controls for restricting which Kubernetes operations are available. These controls are enforced at the tool discovery layer (tools/list) but not at the execution layer (tools/call). Any client that knows a tool name can invoke it directly regardless of the configured restriction mode. The access control was effectively cosmetic. This issue has been patched in version 3.6.0.
CVSS v3.1
Score 8.8high
Affected software
pkg:github/flux159/mcp-server-kubernetesRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in mcp-server-kubernetes involves improper enforcement of access controls defined by environment variables ALLOW_ONLY_READONLY_TOOLS, ALLOW_ONLY_NON_DESTRUCTIVE_TOOLS, and ALLOWED_TOOLS. These controls restrict which Kubernetes operations are available, but enforcement occurs only at the tool discovery layer (tools/list) and not at the execution layer (tools/call). Consequently, any client aware of a tool's name can execute it regardless of configured restrictions, effectively bypassing authorization. This flaw is classified as CWE-863 (Incorrect Authorization). The issue was addressed and patched in version 3.6.0 of mcp-server-kubernetes.
Potential Impact
An attacker with at least limited privileges (PR:L) can bypass intended access restrictions and execute potentially destructive Kubernetes operations, leading to high confidentiality, integrity, and availability impacts. This could allow unauthorized modification or disruption of Kubernetes cluster management functions.
Mitigation Recommendations
Upgrade mcp-server-kubernetes to version 3.6.0 or later, where this authorization bypass vulnerability has been fixed. No other official remediation or temporary fixes are documented. Until upgrading, be aware that environment variable-based access controls are ineffective at preventing unauthorized tool execution.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-05-14T19:12:32.755Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a2b05c8815e7002b81e9b67
Added to database: 6/11/2026, 7:00:24 PM
Last enriched: 6/11/2026, 7:16:22 PM
Last updated: 6/11/2026, 8:19:38 PM
Views: 4
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