CVE-2026-42073
MediumCVSS 6.5Exploitation Probability (EPSS)
Low risk12th percentile - higher than 12% of all known CVEs
Summary
OpenClaude prior to version 0.5.1 contains a logic flaw in the MCP authentication flow that allows an attacker to completely bypass the state parameter validation and force the temporary local HTTP server to shut down, without knowing the state value at all.
Risk Assessment
An attacker can disrupt the authentication server, preventing legitimate users from completing the OAuth flow, leading to denial of service.
Recommendation
It is recommended to immediately update OpenClaude to version 0.5.1 or later.
Other vulnerabilities in OpenClaude
See all- CVE-2026-90712Medium
A vulnerability was identified in Gitlawb openclaude up to 0.30.0. Impacted is the function waitForCallback of the file src/services/api/xaiOAuthCallback.ts of the component xAI OAuth Callback Handler. The manipulation of the argument Error leads to denial of service. Remote exploitation of the attack is possible. The exploit is publicly available and might be used. The project was informed of the problem early through an issue report but has not responded yet.
- CVE-2026-42074Critical
OpenClaude prior to version 0.5.1 exposes the dangerouslyDisableSandbox parameter in the BashTool input schema, allowing a prompt-injected model to escape the sandbox and achieve full host-level code execution.
Original NVD description (English source)
OpenClaude is an open-source coding-agent command line interface for cloud and local model providers. Prior to version 0.5.1, the OpenClaude MCP authentication flow starts a temporary local HTTP server to handle OAuth callbacks. To prevent CSRF attacks, the server validates a state parameter against an internally stored value. However, due to a logic flaw in the order of conditionals, an attacker can completely bypass this check and force the server to shut down — without knowing the state value at all. This issue has been patched in version 0.5.1.