{"id":"CVE-2026-56274","state":"PUBLISHED","title":"Flowise - Remote Code Execution via MCP Security Bypass in validateCommandFlags and validateArgsForLocalFileAccess","description":"Flowise before 3.1.2 contains multiple OS command injection vulnerabilities in the Custom MCP Server feature due to incomplete command-flag validation and a regex bypass in local file access restrictions. An attacker with a Flowise account of any role, or API access with view/update permissions for chatflows, can configure a malicious MCP server to bypass the validateCommandFlags blocklist (for example, 'docker build' is not blocked, and 'npx --yes' is not blocked while only '-y' is) and the validateArgsForLocalFileAccess checks, resulting in execution of arbitrary commands on the Flowise host.","publishedAt":"2026-06-23T12:13:00.703Z","updatedAt":"2026-06-24T11:17:02.895Z","severity":{"score":8.7,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["Flowise Flowise","Flowise Flowise Components"],"affected":[{"vendor":"Flowise","product":"Flowise","packageURL":"pkg:npm/flowise","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"3.1.2","versionType":"semver"},{"version":"3.1.2","status":"unaffected","versionType":"semver"}]},{"vendor":"Flowise","product":"Flowise Components","packageURL":"pkg:npm/flowise-components","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"3.1.2","versionType":"semver"},{"version":"3.1.2","status":"unaffected","versionType":"semver"}]}],"references":["https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-m99r-2hxc-cp3q","https://www.vulncheck.com/advisories/flowise-remote-code-execution-via-mcp-security-bypass-in-validatecommandflags-and-validateargsforlocalfileaccess"],"weaknesses":["CWE-78"],"ingestedAt":"2026-10-29T20:12:24.861Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/56xxx/CVE-2026-56274.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-56274","state":"PUBLISHED","datePublished":"2026-06-23T12:13:00.703Z","dateUpdated":"2026-06-24T11:17:02.895Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-06-20T01:47:54.000Z"},"containers":{"cna":{"title":"Flowise - Remote Code Execution via MCP Security Bypass in validateCommandFlags and validateArgsForLocalFileAccess","descriptions":[{"lang":"en","value":"Flowise before 3.1.2 contains multiple OS command injection vulnerabilities in the Custom MCP Server feature due to incomplete command-flag validation and a regex bypass in local file access restrictions. 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