{"version":"2.1.211","anchor":"callback-port-validation-tightened","canonical_anchor":"callback-port-validation-tightened","heading":"--callback-port Validation Tightened","tier":null,"area":null,"scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.211\/e\/callback-port-validation-tightened","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.211","markdown":"### `--callback-port` Validation Tightened\n\n**What**\n\nThe MCP OAuth callback port flag (`--callback-port`) now validates that the port number falls within the valid TCP range `[1, 65535]`, rather than only checking it is a positive integer.\n\n**Details**\n\n- The error message now reads: \"Error: --callback-port must be an integer in [1, 65535]\"\n- Port 0 is no longer accepted. The validation expression is `!Number.isInteger(m) || m <= 0 || m > 65535`, so port 0, negative values, and non-integer inputs (e.g. `1.5` or non-numeric strings that parse to `NaN`) are all rejected.\n- The same validation is applied in two separate command paths: `claude mcp add` (for SSE and HTTP transports) and `claude mcp oauth identity-provider set`.\n\n**Evidence**\n\nUpdated validation error string (search for `\"--callback-port must be an integer in [1, 65535]\"`)"}