CVE-2026-42073
OpenClaude's MCP OAuth Callback: State Check Bypass via error Param Leads to DoS
CVSS Score
6.5
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-352 CWE-400 |
| Vendor | gitlawb |
| Product | openclaude |
| Published | Jun 2, 2026 |
| Last Updated | Jun 2, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
Gitlawb / openclaude
< 0.5.1