diff --git a/.changeset/fix-mcp-config-shell-injection.md b/.changeset/fix-mcp-config-shell-injection.md
new file mode 100644
index 0000000000..376b96f67d
--- /dev/null
+++ b/.changeset/fix-mcp-config-shell-injection.md
@@ -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)
diff --git a/packages/js-sdk/src/sandbox/index.ts b/packages/js-sdk/src/sandbox/index.ts
index 7384dc7af2..29492a9f1e 100644
--- a/packages/js-sdk/src/sandbox/index.ts
+++ b/packages/js-sdk/src/sandbox/index.ts
@@ -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.
  */
@@ -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 ${shellQuote(JSON.stringify(sandboxOpts.mcp))}`,
         {
           user: 'root',
           envs: {
@@ -394,7 +402,7 @@ export class Sandbox extends SandboxApi {
     if (sandboxOpts?.mcp) {
       sandbox.mcpToken = crypto.randomUUID()
       const res = await sandbox.commands.run(
-        `mcp-gateway --config '${JSON.stringify(sandboxOpts?.mcp)}'`,
+        `mcp-gateway --config ${shellQuote(JSON.stringify(sandboxOpts.mcp))}`,
         {
           user: 'root',
           envs: {
diff --git a/packages/python-sdk/e2b/sandbox_async/main.py b/packages/python-sdk/e2b/sandbox_async/main.py
index 0fe175de3d..3dd7044ea7 100644
--- a/packages/python-sdk/e2b/sandbox_async/main.py
+++ b/packages/python-sdk/e2b/sandbox_async/main.py
@@ -1,6 +1,7 @@
 import datetime
 import json
 import logging
+import shlex
 import uuid
 from typing import Dict, List, Optional, Union, overload
 
@@ -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},
             )
@@ -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},
             )
diff --git a/packages/python-sdk/e2b/sandbox_sync/main.py b/packages/python-sdk/e2b/sandbox_sync/main.py
index a52cb4c303..43f3a858c5 100644
--- a/packages/python-sdk/e2b/sandbox_sync/main.py
+++ b/packages/python-sdk/e2b/sandbox_sync/main.py
@@ -1,6 +1,7 @@
 import datetime
 import json
 import logging
+import shlex
 import uuid
 from typing import Dict, List, Optional, Union, overload
 
@@ -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},
             )
@@ -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},
             )