GHSA-647H-P824-99W7
Vulnerability from github – Published: 2026-03-25 17:23 – Updated: 2026-03-25 17:23Impact
The knowledge_search and knowledge_get_node MCP tools are included in SCOPED_TOOLS (visible to scoped agents) but their handlers do not receive authContext and do not enforce workspace scoping. A scoped agent in Workspace A can supply an arbitrary workspaceId parameter to search or retrieve knowledge graph nodes from Workspace B, bypassing workspace isolation boundaries.
This is a cross-workspace data leakage vulnerability affecting any deployment where multiple workspaces contain sensitive knowledge graph data and scoped agents are used.
Affected code:
- packages/mcp/src/tools/knowledge.ts:146-169 (knowledge_search handler)
- packages/mcp/src/tools/knowledge.ts:244-283 (knowledge_get_node handler)
- packages/mcp/src/tool-scoping.ts:11 (both tools listed in SCOPED_TOOLS)
Contrast with correct implementation: knowledge_create_node (same file, lines 334-357) properly receives authContext and overrides the user-supplied workspaceId for scoped callers.
Design Note
Cross-workspace knowledge sharing is a legitimate future feature — agents working across different repos may need to collaborate and share knowledge. However, this access should be opt-in with explicit grants, not an implicit bypass. The immediate fix locks scoped agents to their own workspace. A future design could introduce:
- Workspace-level "share knowledge with" settings
- A cross_workspace scope on scoped tokens
- Explicit workspaceIds (plural) in the auth context
Patches
Fix: Add authContext parameter to knowledge_search and knowledge_get_node handlers and enforce workspace scoping, matching the pattern in knowledge_create_node:
const resolvedWorkspaceId =
authContext?.type === "scoped"
? authContext.workspaceId ?? ""
: workspaceId ?? "";
When cross-workspace collaboration is designed, this check can be relaxed intentionally with proper access controls.
Workarounds
Do not use scoped agent tokens in multi-workspace deployments until patched. Alternatively, remove knowledge_search and knowledge_get_node from the SCOPED_TOOLS set in tool-scoping.ts.
References
- CWE-284: Improper Access Control
- File:
packages/mcp/src/tools/knowledge.ts - File:
packages/mcp/src/tool-scoping.ts
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 0.70.1"
},
"package": {
"ecosystem": "npm",
"name": "@grackle-ai/mcp"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.70.2"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-284"
],
"github_reviewed": true,
"github_reviewed_at": "2026-03-25T17:23:11Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "### Impact\n\nThe `knowledge_search` and `knowledge_get_node` MCP tools are included in `SCOPED_TOOLS` (visible to scoped agents) but their handlers do not receive `authContext` and do not enforce workspace scoping. A scoped agent in Workspace A can supply an arbitrary `workspaceId` parameter to search or retrieve knowledge graph nodes from Workspace B, bypassing workspace isolation boundaries.\n\nThis is a **cross-workspace data leakage** vulnerability affecting any deployment where multiple workspaces contain sensitive knowledge graph data and scoped agents are used.\n\n**Affected code:**\n- `packages/mcp/src/tools/knowledge.ts:146-169` (knowledge_search handler)\n- `packages/mcp/src/tools/knowledge.ts:244-283` (knowledge_get_node handler)\n- `packages/mcp/src/tool-scoping.ts:11` (both tools listed in SCOPED_TOOLS)\n\n**Contrast with correct implementation:** `knowledge_create_node` (same file, lines 334-357) properly receives `authContext` and overrides the user-supplied `workspaceId` for scoped callers.\n\n### Design Note\n\nCross-workspace knowledge sharing is a legitimate future feature \u2014 agents working across different repos may need to collaborate and share knowledge. However, this access should be **opt-in with explicit grants**, not an implicit bypass. The immediate fix locks scoped agents to their own workspace. A future design could introduce:\n- Workspace-level \"share knowledge with\" settings\n- A `cross_workspace` scope on scoped tokens\n- Explicit `workspaceIds` (plural) in the auth context\n\n### Patches\n\n**Fix:** Add `authContext` parameter to `knowledge_search` and `knowledge_get_node` handlers and enforce workspace scoping, matching the pattern in `knowledge_create_node`:\n```typescript\nconst resolvedWorkspaceId =\n authContext?.type === \"scoped\"\n ? authContext.workspaceId ?? \"\"\n : workspaceId ?? \"\";\n```\n\nWhen cross-workspace collaboration is designed, this check can be relaxed intentionally with proper access controls.\n\n### Workarounds\n\nDo not use scoped agent tokens in multi-workspace deployments until patched. Alternatively, remove `knowledge_search` and `knowledge_get_node` from the `SCOPED_TOOLS` set in `tool-scoping.ts`.\n\n### References\n\n- CWE-284: Improper Access Control\n- File: `packages/mcp/src/tools/knowledge.ts`\n- File: `packages/mcp/src/tool-scoping.ts`",
"id": "GHSA-647h-p824-99w7",
"modified": "2026-03-25T17:23:11Z",
"published": "2026-03-25T17:23:11Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/nick-pape/grackle/security/advisories/GHSA-647h-p824-99w7"
},
{
"type": "PACKAGE",
"url": "https://github.com/nick-pape/grackle"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N",
"type": "CVSS_V4"
}
],
"summary": "@grackle-ai/mcp has a workspace authorization bypass in its knowledge_search MCP tool"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.