Cyberchef MCP Server
cyberchef
npm
v11.2.0
Source verified
Published by gchq — publish provenance cryptographically ties this package to that repository. That is proof of origin, not an official vendor package.
Every server starts at 100. These are the exact deductions the deterministic engine applied — each one reproducible, none of it an opinion or an LLM's guess:
| Points | What was found | Category |
|---|---|---|
| −37.7 | Obfuscated / encoded payload in server code ×10 MTC-SRC-004 | injection |
| −22 | Hardcoded PEM private key in server code MTC-SRC-008 | exfiltration |
| −6.3 | Package runs install-time scripts MTC-SUP-010 | supply-chain |
Grade capped: 1 confirmed high finding → grade capped at C. A hard gate overrides the point total — no amount of clean surface buys back a confirmed catastrophe.
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 the deduction.
Findings 14
high Hardcoded PEM private key in server code (tests/operations/tests/ECDSA.mjs)MTC-SRC-008
A live-looking PEM private key is hardcoded in `tests/operations/tests/ECDSA.mjs:16`. Secrets in source ship to everyone who installs the package and are a direct credential leak.
Evidence: PEM private key: ----…(redacted)
Fix: Remove the secret, rotate it, and load credentials from the environment or a secret store.
Location: server tests/operations/tests/ECDSA.mjs
high Obfuscated / encoded payload in server code (tests/browser/01_io.js)MTC-SRC-004
In the server's implementation (`tests/browser/01_io.js:36`): Decoding an encoded blob and executing it is how malicious logic is hidden from human review of the source. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: \x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f
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 tests/browser/01_io.js
high Obfuscated / encoded payload in server code (tests/operations/tests/AvroToJSON.mjs)MTC-SRC-004
In the server's implementation (`tests/operations/tests/AvroToJSON.mjs:36`): Decoding an encoded blob and executing it is how malicious logic is hidden from human review of the source. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: \x4f\x62\x6a\x01\x04\x16\x61\x76\x72\x6f\x2e\x73\x63\x68\x65\x6d\x61\x96\x01\x7b\x22\x74\x79\x70\x65\x22\x3a\x22\x72\x65
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 tests/operations/tests/AvroToJSON.mjs
high Obfuscated / encoded payload in server code (tests/operations/tests/Base32.mjs)MTC-SRC-004
In the server's implementation (`tests/operations/tests/Base32.mjs:21`): Decoding an encoded blob and executing it is how malicious logic is hidden from human review of the source. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: \x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f
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 tests/operations/tests/Base32.mjs
high Obfuscated / encoded payload in server code (tests/operations/tests/Base64.mjs)MTC-SRC-004
In the server's implementation (`tests/operations/tests/Base64.mjs:12`): Decoding an encoded blob and executing it is how malicious logic is hidden from human review of the source. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: \x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f
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 tests/operations/tests/Base64.mjs
high Obfuscated / encoded payload in server code (tests/operations/tests/Base85.mjs)MTC-SRC-004
In the server's implementation (`tests/operations/tests/Base85.mjs:19`): Decoding an encoded blob and executing it is how malicious logic is hidden from human review of the source. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: \x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f
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 tests/operations/tests/Base85.mjs
high Obfuscated / encoded payload in server code (tests/operations/tests/ByteRepr.mjs)MTC-SRC-004
In the server's implementation (`tests/operations/tests/ByteRepr.mjs:11`): Decoding an encoded blob and executing it is how malicious logic is hidden from human review of the source. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: \x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f
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 tests/operations/tests/ByteRepr.mjs
high Obfuscated / encoded payload in server code (tests/operations/tests/CRCChecksum.mjs)MTC-SRC-004
In the server's implementation (`tests/operations/tests/CRCChecksum.mjs:11`): Decoding an encoded blob and executing it is how malicious logic is hidden from human review of the source. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: \x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f
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 tests/operations/tests/CRCChecksum.mjs
high Obfuscated / encoded payload in server code (tests/operations/tests/CaretMdecode.mjs)MTC-SRC-004
In the server's implementation (`tests/operations/tests/CaretMdecode.mjs:30`): Decoding an encoded blob and executing it is how malicious logic is hidden from human review of the source. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: \x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f\x20\x21\x22\x23\x24\x25\x26\x27
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 tests/operations/tests/CaretMdecode.mjs
high Obfuscated / encoded payload in server code (tests/operations/tests/CipherSaber2.mjs)MTC-SRC-004
In the server's implementation (`tests/operations/tests/CipherSaber2.mjs:26`): Decoding an encoded blob and executing it is how malicious logic is hidden from human review of the source. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: \x6f\x6d\x0b\xab\xf3\xaa\x67\x19\x03\x15\x30\xed\xb6\x77
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 tests/operations/tests/CipherSaber2.mjs
high Obfuscated / encoded payload in server code (tests/operations/tests/Comment.mjs)MTC-SRC-004
In the server's implementation (`tests/operations/tests/Comment.mjs:12`): Decoding an encoded blob and executing it is how malicious logic is hidden from human review of the source. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: \x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f
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 tests/operations/tests/Comment.mjs
high Shell/command execution in server code (tests/operations/tests/Code.mjs)MTC-SRC-002
In the server's implementation (`tests/operations/tests/Code.mjs:334`): Spawning a shell/process is command-execution capability; with unsanitized tool input it is command injection / RCE. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: child_process
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 tests/operations/tests/Code.mjs
high Shell/command execution in server code (webpack.config.js)MTC-SRC-002
In the server's implementation (`webpack.config.js:125`): Spawning a shell/process is command-execution capability; with unsanitized tool input it is command injection / RCE. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.
Evidence: child_process
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 webpack.config.js
medium Package runs install-time scripts (postinstall)MTC-SUP-010
"cyberchef" executes postinstall script(s) at install time. The large majority of malicious packages abuse install hooks to run code before you ever import them.
Fix: Review the scripts; install with --ignore-scripts where possible and vet what they do.
Location: package cyberchef
What this scan could not see
- No tools were enumerated, so prompt-injection, capability and toxic-flow analysis had no tool surface to inspect. To grade a package’s real runtime tools, scan the running server: --command "npx -y <package>".
Versions
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 |
|---|---|---|---|---|
v11.2.0 latest |
F 34/100 | 14 | 1.5.0 | 2026-07-22 |
Embed this score
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Verify this score yourself
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