{"id":"CVE-2026-42073","summary":"OpenClaude's MCP OAuth Callback: State Check Bypass via error Param Leads to DoS","details":"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.","aliases":["GHSA-c73c-x77g-854r"],"modified":"2026-07-08T08:13:18.670380990Z","published":"2026-06-02T15:38:53.435Z","database_specific":{"cwe_ids":["CWE-352","CWE-400"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42073.json","cna_assigner":"GitHub_M"},"references":[{"type":"WEB","url":"https://github.com/Gitlawb/openclaude/releases/tag/v0.5.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42073.json"},{"type":"ADVISORY","url":"https://github.com/Gitlawb/openclaude/security/advisories/GHSA-c73c-x77g-854r"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42073"},{"type":"FIX","url":"https://github.com/Gitlawb/openclaude/commit/739b8d1f40fde0e401a5cbd2b9a55d88bd5124ad"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/gitlawb/openclaude","events":[{"introduced":"0"},{"fixed":"c0b8a59a2377ebf49389d3e6adf41e6d255cb975"},{"fixed":"739b8d1f40fde0e401a5cbd2b9a55d88bd5124ad"}],"database_specific":{"cpe":"cpe:2.3:a:gitlawb:openclaude:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"0"},{"fixed":"0.5.1"}],"source":["CPE_RANGE","REFERENCES"]}}],"versions":["v0.5.0","v0.4.0","v0.3.0","v0.2.3","v0.2.2","v0.2.1","v0.2.0","v0.1.8","v0.1.6","v0.1.7"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-42073.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"}]}