Answer in brief
CVE-2026-88257 records a Medium severity (CVSS 5.3) vulnerability in beam_mcp: nested tool argument constraints advertised but not enforced. The current sources do not mark it as known exploited. The current feed maps ScriptKittyOS/beam_mcp (generic), ScriptKittyOS/scriptkittyos/beam_mcp (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.3. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps ScriptKittyOS/beam_mcp (generic), ScriptKittyOS/scriptkittyos/beam_mcp (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| ScriptKittyOS/beam_mcpgeneric | >=0.1.0 <0.10.1 | 0.10.1 |
| ScriptKittyOS/scriptkittyos/beam_mcpgeneric | >=083838eb8e17fe5f6fcaf761bdbe203110288b0b <289dbdbad641943b29a3b8d1eb36506cc8cec10a | 289dbdbad641943b29a3b8d1eb36506cc8cec10a |
Published upstream
Oct 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Oct 8, 2026
Improper Input Validation vulnerability in BeamMCP.Schema in ScriptKittyOS beam_mcp allows an MCP client to reach a tool's 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. A 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. This issue affects beam_mcp: from 0.1.0 before 0.10.1.
Quoted source text, attributed separately from HOL analysis.