Celavii M365 MCP Server
celavii-m365
npm
v0.5.0
Source verified
Published by celaviihq — publish provenance cryptographically ties this package to that repository. That is proof of origin, not an official vendor package.
The grade answers one question — how safe is this server for you to adopt — so it is computed in two auditable stages. Nothing below is an opinion or an LLM's guess; every line is a real term the deterministic engine applied, and the same input always yields the same number.
1. Threat score — 100 − 0 = 100. What the published surface and source actually contain:
The deterministic scan raised no scored threat in the surface it inspected — the threat score stayed at 100. Capability observations and advisory notes are recorded but never lower it.
2. Client adoption risk — 100 − 6 = 94. Three small, subtract-only factors that reflect your risk in adopting it — a clean scan proves less on a powerful, unverified or barely-inspectable package, so the grade says so plainly:
| Points | Adoption-risk factor |
|---|---|
| −6 | capability blast radius (high) — client exposure if the model is manipulated |
Capability observations and info notes are shown under Findings but never scored.
Open any row's finding below for the file, line and evidence behind a deduction.
Findings 4
critical Completed toxic-flow trifecta across toolsMTC-FLOW-002
This server (without client built-ins) exposes a complete data-exfiltration chain: m365_onedrive_download → m365_onedrive_list → m365_draft_email. Untrusted input is ingested, private data is read, and it can be sent to an external sink via the agent composing the tools (→). Static analysis proves the primitive exists, not that a specific run will occur.
Fix: Remove one leg of the trifecta: isolate untrusted-input tools from secret-reading tools and from egress tools, or require human approval between them.
Location: flow m365_onedrive_download → m365_onedrive_list → m365_draft_email
medium Hardcoded egress to an external endpoint (dist/auth-server.js)MTC-SRC-003
In the server's implementation (`dist/auth-server.js:88`): A hardcoded outbound call to a fixed external host inside server code is a classic exfiltration/telemetry channel — especially paired with reads of local data. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: ; const res = await fetch( `https://login.microsoftonline.com/${this.config.tenantId}/oauth2/v2.0/token`,
Fix: Review this call path: confirm it never receives unsanitized tool input, constrain it, or remove it. Treat a server whose code reaches these sinks as high-capability regardless of what its tools claim.
Location: server dist/auth-server.js
medium Hardcoded egress to an external endpoint (dist/index.js)MTC-SRC-003
In the server's implementation (`dist/index.js:298`): A hardcoded outbound call to a fixed external host inside server code is a classic exfiltration/telemetry channel — especially paired with reads of local data. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: ; const res = await fetch( `https://login.microsoftonline.com/${this.config.tenantId}/oauth2/v2.0/token`,
Fix: Review this call path: confirm it never receives unsanitized tool input, constrain it, or remove it. Treat a server whose code reaches these sinks as high-capability regardless of what its tools claim.
Location: server dist/index.js
medium Hardcoded egress to an external endpoint (dist/remote/index.js)MTC-SRC-003
In the server's implementation (`dist/remote/index.js:296`): A hardcoded outbound call to a fixed external host inside server code is a classic exfiltration/telemetry channel — especially paired with reads of local data. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: ; const res = await fetch( `https://login.microsoftonline.com/${this.config.tenantId}/oauth2/v2.0/token`,
Fix: Review this call path: confirm it never receives unsanitized tool input, constrain it, or remove it. Treat a server whose code reaches these sinks as high-capability regardless of what its tools claim.
Location: server dist/remote/index.js
Tools 36
Each tool and what it can reach — statically extracted from the published source.
m365_draft_emailnetwork egressm365_onedrive_downloadingests untrusted inputm365_onedrive_listreads sensitive datam365_read_emailingests untrusted inputm365_send_emailnetwork egressm365_aboutno sensitive capabilitym365_accept_eventno sensitive capabilitym365_authenticateno sensitive capabilitym365_cancel_eventno sensitive capabilitym365_check_auth_statusno sensitive capability
Show 26 more tools ↓
m365_create_eventno sensitive capabilitym365_create_folderno sensitive capabilitym365_create_ruleno sensitive capabilitym365_decline_eventno sensitive capabilitym365_delete_eventno sensitive capabilitym365_delete_ruleno sensitive capabilitym365_flow_listno sensitive capabilitym365_flow_list_environmentsno sensitive capabilitym365_flow_list_runsno sensitive capabilitym365_flow_runno sensitive capabilitym365_flow_toggleno sensitive capabilitym365_list_emailsno sensitive capabilitym365_list_eventsno sensitive capabilitym365_list_foldersno sensitive capabilitym365_list_rulesno sensitive capabilitym365_logoutno sensitive capabilitym365_mark_as_readno sensitive capabilitym365_move_emailsno sensitive capabilitym365_onedrive_create_folderno sensitive capabilitym365_onedrive_deleteno sensitive capabilitym365_onedrive_searchno sensitive capabilitym365_onedrive_shareno sensitive capabilitym365_onedrive_uploadno sensitive capabilitym365_search_emailsno sensitive capabilitym365_send_draftno sensitive capabilitym365_update_rule_sequenceno sensitive capability
Toxic flows 1
Cross-tool combinations that form a data-exfiltration primitive (untrusted input → sensitive source → external sink).
What this scan could not see
- Tools were statically extracted from the published source (36 recovered), not enumerated from a running server. Tool-poisoning, Unicode-smuggling, capability and toxic-flow analysis ran on this inferred surface, but a mis-parsed registration could be missed or mis-attributed, so tool-derived findings are capped below “confirmed”. To grade the real runtime surface, scan the running server: --command "npx -y <package>".
Versions 1
Scan history per published version. The engine is deterministic — the same version always yields the same score, so a changed score means the package itself changed.
| Version | Score | Findings | Engine | Scanned |
|---|---|---|---|---|
v0.5.0 latest |
A 94/100 | 4 | 1.9.0 | 2026-07-24 |
Embed this score
Show this server's live Trust Score in your README, docs or website. The badge is served straight from the registry and updates automatically after every rescan — no API key needed. It links back to this page, so anyone who sees the grade can also read the findings behind it instead of taking a number on faith.
Verify this score yourself
The score above is reproducible: the same package version always yields the same result. Run it locally or over the free API — no account, no LLM, fully deterministic.
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