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fix(sdk): prevent shell injection in MCP config via proper escaping #1276

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fix(sdk): prevent shell injection in MCP config via proper escaping #1276

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850b344
fix(sdk): prevent shell injection in MCP config via shlex.quote / she…
kagura-agent Apr 17, 2026
7bfaf28
chore: add changeset for shell injection fix
kagura-agent Apr 17, 2026
89fe756
chore: remove accidental package-lock.json
kagura-agent Apr 17, 2026
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5 changes: 5 additions & 0 deletions .changeset/fix-mcp-config-shell-injection.md
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Original file line number Diff line number Diff line change
@@ -0,0 +1,5 @@
---
"e2b": patch
---

fix(sdk): prevent shell injection in MCP config by using proper shell escaping (shlex.quote in Python, shellQuote helper in JS/TS)
12 changes: 10 additions & 2 deletions packages/js-sdk/src/sandbox/index.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,14 @@ import { compareVersions } from 'compare-versions'
import { SandboxError } from '../errors'
import { ENVD_DEBUG_FALLBACK, ENVD_DEFAULT_USER } from '../envd/versions'

/**
* Escape a string for safe inclusion in a single-quoted shell argument.
* Equivalent to Python's shlex.quote().
*/
function shellQuote(s: string): string {
return "'" + s.replace(/'/g, "'\\''") + "'"
}

/**
* Options for sandbox upload/download URL generation.
*/
Expand Down Expand Up @@ -299,7 +307,7 @@ export class Sandbox extends SandboxApi {
if (sandboxOpts?.mcp) {
sandbox.mcpToken = crypto.randomUUID()
const res = await sandbox.commands.run(
`mcp-gateway --config '${JSON.stringify(sandboxOpts?.mcp)}'`,
`mcp-gateway --config ${shellQuote(JSON.stringify(sandboxOpts.mcp))}`,
{
user: 'root',
envs: {
Expand Down Expand Up @@ -394,7 +402,7 @@ export class Sandbox extends SandboxApi {
if (sandboxOpts?.mcp) {
sandbox.mcpToken = crypto.randomUUID()
const res = await sandbox.commands.run(
`mcp-gateway --config '${JSON.stringify(sandboxOpts?.mcp)}'`,
`mcp-gateway --config ${shellQuote(JSON.stringify(sandboxOpts.mcp))}`,
{
user: 'root',
envs: {
Expand Down
5 changes: 3 additions & 2 deletions packages/python-sdk/e2b/sandbox_async/main.py
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Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
import datetime
import json
import logging
import shlex
import uuid
from typing import Dict, List, Optional, Union, overload

Expand Down Expand Up @@ -235,7 +236,7 @@ async def create(
sandbox._mcp_token = token

res = await sandbox.commands.run(
f"mcp-gateway --config '{json.dumps(mcp)}'",
f"mcp-gateway --config {shlex.quote(json.dumps(mcp))}",
user="root",
envs={"GATEWAY_ACCESS_TOKEN": token},
)
Expand Down Expand Up @@ -616,7 +617,7 @@ async def beta_create(
sandbox._mcp_token = token

res = await sandbox.commands.run(
f"mcp-gateway --config '{json.dumps(mcp)}'",
f"mcp-gateway --config {shlex.quote(json.dumps(mcp))}",
user="root",
envs={"GATEWAY_ACCESS_TOKEN": token},
)
Expand Down
5 changes: 3 additions & 2 deletions packages/python-sdk/e2b/sandbox_sync/main.py
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Original file line number Diff line number Diff line change
@@ -1,6 +1,7 @@
import datetime
import json
import logging
import shlex
import uuid
from typing import Dict, List, Optional, Union, overload

Expand Down Expand Up @@ -233,7 +234,7 @@ def create(
sandbox._mcp_token = token

res = sandbox.commands.run(
f"mcp-gateway --config '{json.dumps(mcp)}'",
f"mcp-gateway --config {shlex.quote(json.dumps(mcp))}",
user="root",
envs={"GATEWAY_ACCESS_TOKEN": token},
)
Expand Down Expand Up @@ -617,7 +618,7 @@ def beta_create(
sandbox._mcp_token = token

res = sandbox.commands.run(
f"mcp-gateway --config '{json.dumps(mcp)}'",
f"mcp-gateway --config {shlex.quote(json.dumps(mcp))}",
user="root",
envs={"GATEWAY_ACCESS_TOKEN": token},
)
Expand Down