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          "shortName": "CISA-ADP"
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              "value": "\u003cp\u003eImproper Input Validation vulnerability in \u003ccode\u003eBeamMCP.Schema\u003c/code\u003e in ScriptKittyOS beam_mcp allows an MCP client to reach a tool\u0027s dispatch function with arguments that violate the input schema the server advertised. \u003ccode\u003eBeamMCP.Schema.validate/2\u003c/code\u003e checked \u003ccode\u003etype\u003c/code\u003e, \u003ccode\u003erequired\u003c/code\u003e, \u003ccode\u003eadditionalProperties\u003c/code\u003e, \u003ccode\u003eenum\u003c/code\u003e and numeric bounds on the top-level arguments object only. Constraints inside nested objects and on array items (\u003ccode\u003eitems\u003c/code\u003e, \u003ccode\u003eminItems\u003c/code\u003e, \u003ccode\u003emaxItems\u003c/code\u003e, \u003ccode\u003eminLength\u003c/code\u003e, \u003ccode\u003emaxLength\u003c/code\u003e, \u003ccode\u003epattern\u003c/code\u003e, nested \u003ccode\u003erequired\u003c/code\u003e, \u003ccode\u003eenum\u003c/code\u003e and \u003ccode\u003eadditionalProperties: false\u003c/code\u003e) were advertised by \u003ccode\u003etools/list\u003c/code\u003e and never checked at \u003ccode\u003etools/call\u003c/code\u003e or \u003ccode\u003eprompts/get\u003c/code\u003e, and keywords outside the enforced subset (\u003ccode\u003eoneOf\u003c/code\u003e, \u003ccode\u003eanyOf\u003c/code\u003e, \u003ccode\u003e$ref\u003c/code\u003e) were advertised and ignored.\u003c/p\u003e\n\u003cp\u003eA host whose dispatch code relies on the schema it declared receives values the schema forbids, such as an out-of-range number or an undeclared key inside a nested object. What the host does with such a value decides the impact.\u003c/p\u003e\n\u003cp\u003eThis issue affects beam_mcp: from 0.1.0 before 0.10.1.\u003c/p\u003e"
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              "value": "Improper Input Validation vulnerability in `BeamMCP.Schema` in ScriptKittyOS beam_mcp allows an MCP client to reach a tool\u0027s dispatch function with arguments that violate the input schema the server advertised. `BeamMCP.Schema.validate/2` checked `type`, `required`, `additionalProperties`, `enum` and numeric bounds on the top-level arguments object only. Constraints inside nested objects and on array items (`items`, `minItems`, `maxItems`, `minLength`, `maxLength`, `pattern`, nested `required`, `enum` and `additionalProperties: false`) were advertised by `tools/list` and never checked at `tools/call` or `prompts/get`, and keywords outside the enforced subset (`oneOf`, `anyOf`, `$ref`) were advertised and ignored.\n\nA host whose dispatch code relies on the schema it declared receives values the schema forbids, such as an out-of-range number or an undeclared key inside a nested object. What the host does with such a value decides the impact.\n\nThis issue affects beam_mcp: from 0.1.0 before 0.10.1."
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      "title": "beam_mcp: nested tool argument constraints advertised but not enforced",
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              "value": "\u003cp\u003eRe-validate the arguments inside the host\u0027s dispatch function against every constraint the schema declares below the top level, or move each constraint to a top-level property, which the affected versions do enforce.\u003c/p\u003e"
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              "value": "1. Declare a tool whose `input_schema` has a nested object property `opts` with `\"properties\": {\"level\": {\"type\": \"integer\", \"maximum\": 3}}`, `\"required\": [\"level\"]` and `\"additionalProperties\": false`, and an array property `tags` with `\"items\": {\"type\": \"string\"}` and `\"maxItems\": 2`.\n2. Send `tools/call` with `\"arguments\": {\"opts\": {\"level\": 99, \"extra\": \"x\"}}`.\n3. On beam_mcp 0.10.0 the dispatch function receives `%{opts: %{\"extra\" =\u003e \"x\", \"level\" =\u003e 99}}`. On 0.10.1 the call is refused with `invalid arguments: unknown property: opts.extra`.\n4. Send `\"arguments\": {\"tags\": [1, 2, 3]}`. On 0.10.0 the dispatch function receives `tags: [1, 2, 3]`. On 0.10.1 the call is refused with `tags must have at most 2 items`."
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              "value": "**1. Advertising.** `tools/list` returns each tool\u0027s `input_schema` verbatim, including nested `properties`, `items` and constraint keywords.\n\n**2. Validation.** `BeamMCP.Schema.validate/2` in `lib/beam_mcp/schema.ex` walks only the first level: `check_required/2` and `check_additional/3` run on the top-level object, and `check_properties/2` applies `check_type`, `check_enum` and `check_range` to each top-level value. A value of type `object` or `array` is accepted once its own type matches, and its contents are not visited. Keywords the validator does not know are ignored.\n\n**3. Dispatch.** `BeamMCP.Server.validate_and_dispatch/3` passes the accepted arguments to `normalize_arguments/2` and then to the host\u0027s dispatch function, so an undeclared key inside a nested object, an out-of-range nested number, or an array item of the wrong type reaches host code that believed the schema excluded it. The same validator runs on `prompts/get` arguments. The fix in 0.10.1 enforces every keyword of the documented subset at every depth and refuses a schema that uses any other keyword when the catalog is loaded."
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BeamMCP.Schema.validate/2 checked type, required, additionalProperties, enum and numeric bounds on the top-level arguments object only. Constraints inside nested objects and on array items (items, minItems, maxItems, minLength, maxLength, pattern, nested required, enum and additionalProperties: false) were advertised by tools/list and never checked at tools/call or prompts/get, and keywords outside the enforced subset (oneOf, anyOf, $ref) were advertised and ignored.\\n\\nA host whose dispatch code relies on the schema it declared receives values the schema forbids, such as an out-of-range number or an undeclared key inside a nested object. What the host does with such a value decides the impact.\\n\\nThis issue affects beam_mcp: from 0.1.0 before 0.10.1.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"\u003cp\u003eImproper Input Validation vulnerability in \u003ccode\u003eBeamMCP.Schema\u003c/code\u003e in ScriptKittyOS beam_mcp allows an MCP client to reach a tool\u0027s dispatch function with arguments that violate the input schema the server advertised. \u003ccode\u003eBeamMCP.Schema.validate/2\u003c/code\u003e checked \u003ccode\u003etype\u003c/code\u003e, \u003ccode\u003erequired\u003c/code\u003e, \u003ccode\u003eadditionalProperties\u003c/code\u003e, \u003ccode\u003eenum\u003c/code\u003e and numeric bounds on the top-level arguments object only. Constraints inside nested objects and on array items (\u003ccode\u003eitems\u003c/code\u003e, \u003ccode\u003eminItems\u003c/code\u003e, \u003ccode\u003emaxItems\u003c/code\u003e, \u003ccode\u003eminLength\u003c/code\u003e, \u003ccode\u003emaxLength\u003c/code\u003e, \u003ccode\u003epattern\u003c/code\u003e, nested \u003ccode\u003erequired\u003c/code\u003e, \u003ccode\u003eenum\u003c/code\u003e and \u003ccode\u003eadditionalProperties: false\u003c/code\u003e) were advertised by \u003ccode\u003etools/list\u003c/code\u003e and never checked at \u003ccode\u003etools/call\u003c/code\u003e or \u003ccode\u003eprompts/get\u003c/code\u003e, and keywords outside the enforced subset (\u003ccode\u003eoneOf\u003c/code\u003e, \u003ccode\u003eanyOf\u003c/code\u003e, \u003ccode\u003e$ref\u003c/code\u003e) were advertised and ignored.\u003c/p\u003e\\n\u003cp\u003eA host whose dispatch code relies on the schema it declared receives values the schema forbids, such as an out-of-range number or an undeclared key inside a nested object. What the host does with such a value decides the impact.\u003c/p\u003e\\n\u003cp\u003eThis issue affects beam_mcp: from 0.1.0 before 0.10.1.\u003c/p\u003e\", \"base64\": false}, {\"type\": \"text/markdown\", \"value\": \"Improper Input Validation vulnerability in `BeamMCP.Schema` in ScriptKittyOS beam_mcp allows an MCP client to reach a tool\u0027s dispatch function with arguments that violate the input schema the server advertised. `BeamMCP.Schema.validate/2` checked `type`, `required`, `additionalProperties`, `enum` and numeric bounds on the top-level arguments object only. Constraints inside nested objects and on array items (`items`, `minItems`, `maxItems`, `minLength`, `maxLength`, `pattern`, nested `required`, `enum` and `additionalProperties: false`) were advertised by `tools/list` and never checked at `tools/call` or `prompts/get`, and keywords outside the enforced subset (`oneOf`, `anyOf`, `$ref`) were advertised and ignored.\\n\\nA host whose dispatch code relies on the schema it declared receives values the schema forbids, such as an out-of-range number or an undeclared key inside a nested object. What the host does with such a value decides the impact.\\n\\nThis issue affects beam_mcp: from 0.1.0 before 0.10.1.\", \"base64\": false}]}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-20\", \"description\": \"CWE-20 Improper Input Validation\"}]}], \"cpeApplicability\": [{\"nodes\": [{\"negate\": false, \"cpeMatch\": [{\"criteria\": \"cpe:2.3:a:scriptkittyos:beam_mcp:*:*:*:*:*:*:*:*\", \"vulnerable\": true, \"versionEndExcluding\": \"0.10.1\", \"versionStartIncluding\": \"0.1.0\"}], \"operator\": \"OR\"}], \"operator\": \"AND\"}], \"providerMetadata\": {\"orgId\": \"6b3ad84c-e1a6-4bf7-a703-f496b71e49db\", \"shortName\": \"EEF\", \"dateUpdated\": \"2026-10-08T14:09:41.540Z\"}, \"x_proofOfConcept\": [{\"lang\": \"en\", \"value\": \"* Declare a tool whose input_schema has a nested object property opts with \\\"properties\\\": {\\\"level\\\": {\\\"type\\\": \\\"integer\\\", \\\"maximum\\\": 3}}, \\\"required\\\": [\\\"level\\\"] and \\\"additionalProperties\\\": false, and an array property tags with \\\"items\\\": {\\\"type\\\": \\\"string\\\"} and \\\"maxItems\\\": 2.\\n* Send tools/call with \\\"arguments\\\": {\\\"opts\\\": {\\\"level\\\": 99, \\\"extra\\\": \\\"x\\\"}}.\\n* On beam_mcp 0.10.0 the dispatch function receives %{opts: %{\\\"extra\\\" =\u003e \\\"x\\\", \\\"level\\\" =\u003e 99}}. On 0.10.1 the call is refused with invalid arguments: unknown property: opts.extra.\\n* Send \\\"arguments\\\": {\\\"tags\\\": [1, 2, 3]}. On 0.10.0 the dispatch function receives tags: [1, 2, 3]. On 0.10.1 the call is refused with tags must have at most 2 items.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"\u003col\u003e\\n\u003cli\u003eDeclare a tool whose \u003ccode\u003einput_schema\u003c/code\u003e has a nested object property \u003ccode\u003eopts\u003c/code\u003e with \u003ccode\u003e\\\"properties\\\": {\\\"level\\\": {\\\"type\\\": \\\"integer\\\", \\\"maximum\\\": 3}}\u003c/code\u003e, \u003ccode\u003e\\\"required\\\": [\\\"level\\\"]\u003c/code\u003e and \u003ccode\u003e\\\"additionalProperties\\\": false\u003c/code\u003e, and an array property \u003ccode\u003etags\u003c/code\u003e with \u003ccode\u003e\\\"items\\\": {\\\"type\\\": \\\"string\\\"}\u003c/code\u003e and \u003ccode\u003e\\\"maxItems\\\": 2\u003c/code\u003e.\u003c/li\u003e\\n\u003cli\u003eSend \u003ccode\u003etools/call\u003c/code\u003e with \u003ccode\u003e\\\"arguments\\\": {\\\"opts\\\": {\\\"level\\\": 99, \\\"extra\\\": \\\"x\\\"}}\u003c/code\u003e.\u003c/li\u003e\\n\u003cli\u003eOn beam_mcp 0.10.0 the dispatch function receives \u003ccode\u003e%{opts: %{\\\"extra\\\" =\u0026gt; \\\"x\\\", \\\"level\\\" =\u0026gt; 99}}\u003c/code\u003e. On 0.10.1 the call is refused with \u003ccode\u003einvalid arguments: unknown property: opts.extra\u003c/code\u003e.\u003c/li\u003e\\n\u003cli\u003eSend \u003ccode\u003e\\\"arguments\\\": {\\\"tags\\\": [1, 2, 3]}\u003c/code\u003e. On 0.10.0 the dispatch function receives \u003ccode\u003etags: [1, 2, 3]\u003c/code\u003e. On 0.10.1 the call is refused with \u003ccode\u003etags must have at most 2 items\u003c/code\u003e.\u003c/li\u003e\\n\u003c/ol\u003e\", \"base64\": false}, {\"type\": \"text/markdown\", \"value\": \"1. Declare a tool whose `input_schema` has a nested object property `opts` with `\\\"properties\\\": {\\\"level\\\": {\\\"type\\\": \\\"integer\\\", \\\"maximum\\\": 3}}`, `\\\"required\\\": [\\\"level\\\"]` and `\\\"additionalProperties\\\": false`, and an array property `tags` with `\\\"items\\\": {\\\"type\\\": \\\"string\\\"}` and `\\\"maxItems\\\": 2`.\\n2. Send `tools/call` with `\\\"arguments\\\": {\\\"opts\\\": {\\\"level\\\": 99, \\\"extra\\\": \\\"x\\\"}}`.\\n3. On beam_mcp 0.10.0 the dispatch function receives `%{opts: %{\\\"extra\\\" =\u003e \\\"x\\\", \\\"level\\\" =\u003e 99}}`. On 0.10.1 the call is refused with `invalid arguments: unknown property: opts.extra`.\\n4. Send `\\\"arguments\\\": {\\\"tags\\\": [1, 2, 3]}`. On 0.10.0 the dispatch function receives `tags: [1, 2, 3]`. On 0.10.1 the call is refused with `tags must have at most 2 items`.\", \"base64\": false}]}], \"x_technicalAnalysis\": [{\"lang\": \"en\", \"value\": \"1. Advertising. tools/list returns each tool\u0027s input_schema verbatim, including nested properties, items and constraint keywords.\\n\\n2. Validation. BeamMCP.Schema.validate/2 in lib/beam_mcp/schema.ex walks only the first level: check_required/2 and check_additional/3 run on the top-level object, and check_properties/2 applies check_type, check_enum and check_range to each top-level value. A value of type object or array is accepted once its own type matches, and its contents are not visited. Keywords the validator does not know are ignored.\\n\\n3. Dispatch. BeamMCP.Server.validate_and_dispatch/3 passes the accepted arguments to normalize_arguments/2 and then to the host\u0027s dispatch function, so an undeclared key inside a nested object, an out-of-range nested number, or an array item of the wrong type reaches host code that believed the schema excluded it. The same validator runs on prompts/get arguments. The fix in 0.10.1 enforces every keyword of the documented subset at every depth and refuses a schema that uses any other keyword when the catalog is loaded.\", \"supportingMedia\": [{\"type\": \"text/html\", \"value\": \"\u003cp\u003e\u003cstrong\u003e1. Advertising.\u003c/strong\u003e \u003ccode\u003etools/list\u003c/code\u003e returns each tool\u0027s \u003ccode\u003einput_schema\u003c/code\u003e verbatim, including nested \u003ccode\u003eproperties\u003c/code\u003e, \u003ccode\u003eitems\u003c/code\u003e and constraint keywords.\u003c/p\u003e\\n\u003cp\u003e\u003cstrong\u003e2. Validation.\u003c/strong\u003e \u003ccode\u003eBeamMCP.Schema.validate/2\u003c/code\u003e in \u003ccode\u003elib/beam_mcp/schema.ex\u003c/code\u003e walks only the first level: \u003ccode\u003echeck_required/2\u003c/code\u003e and \u003ccode\u003echeck_additional/3\u003c/code\u003e run on the top-level object, and \u003ccode\u003echeck_properties/2\u003c/code\u003e applies \u003ccode\u003echeck_type\u003c/code\u003e, \u003ccode\u003echeck_enum\u003c/code\u003e and \u003ccode\u003echeck_range\u003c/code\u003e to each top-level value. A value of type \u003ccode\u003eobject\u003c/code\u003e or \u003ccode\u003earray\u003c/code\u003e is accepted once its own type matches, and its contents are not visited. Keywords the validator does not know are ignored.\u003c/p\u003e\\n\u003cp\u003e\u003cstrong\u003e3. Dispatch.\u003c/strong\u003e \u003ccode\u003eBeamMCP.Server.validate_and_dispatch/3\u003c/code\u003e passes the accepted arguments to \u003ccode\u003enormalize_arguments/2\u003c/code\u003e and then to the host\u0027s dispatch function, so an undeclared key inside a nested object, an out-of-range nested number, or an array item of the wrong type reaches host code that believed the schema excluded it. The same validator runs on \u003ccode\u003eprompts/get\u003c/code\u003e arguments. The fix in 0.10.1 enforces every keyword of the documented subset at every depth and refuses a schema that uses any other keyword when the catalog is loaded.\u003c/p\u003e\", \"base64\": false}, {\"type\": \"text/markdown\", \"value\": \"**1. Advertising.** `tools/list` returns each tool\u0027s `input_schema` verbatim, including nested `properties`, `items` and constraint keywords.\\n\\n**2. Validation.** `BeamMCP.Schema.validate/2` in `lib/beam_mcp/schema.ex` walks only the first level: `check_required/2` and `check_additional/3` run on the top-level object, and `check_properties/2` applies `check_type`, `check_enum` and `check_range` to each top-level value. A value of type `object` or `array` is accepted once its own type matches, and its contents are not visited. Keywords the validator does not know are ignored.\\n\\n**3. Dispatch.** `BeamMCP.Server.validate_and_dispatch/3` passes the accepted arguments to `normalize_arguments/2` and then to the host\u0027s dispatch function, so an undeclared key inside a nested object, an out-of-range nested number, or an array item of the wrong type reaches host code that believed the schema excluded it. The same validator runs on `prompts/get` arguments. The fix in 0.10.1 enforces every keyword of the documented subset at every depth and refuses a schema that uses any other keyword when the catalog is loaded.\", \"base64\": false}]}]}}",
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