diff --git a/packages/core/scripts/expo-upload-sourcemaps.js b/packages/core/scripts/expo-upload-sourcemaps.js
index d33afc95f6..90a16aa057 100755
--- a/packages/core/scripts/expo-upload-sourcemaps.js
+++ b/packages/core/scripts/expo-upload-sourcemaps.js
@@ -1,5 +1,5 @@
 #!/usr/bin/env node
-const { execSync } = require('child_process');
+const { spawnSync } = require('child_process');
 const fs = require('fs');
 const path = require('path');
 const process = require('process');
@@ -16,8 +16,11 @@ function getEnvVar(varname) {
 
 function getSentryPluginPropertiesFromExpoConfig() {
   try {
-    const stdOutBuffer = execSync('npx expo config --json');
-    const config = JSON.parse(stdOutBuffer.toString());
+    const result = spawnSync('npx', ['expo', 'config', '--json'], { encoding: 'utf8' });
+    if (result.error || result.status !== 0) {
+      throw result.error || new Error(`expo config exited with status ${result.status}`);
+    }
+    const config = JSON.parse(result.stdout);
     const plugins = config.plugins;
     if (!plugins) {
       return null;
@@ -217,8 +220,15 @@ for (const [assetGroupName, assets] of Object.entries(groupedAssets)) {
   }
 
   const isHermes = assets.find(asset => asset.endsWith('.hbc'));
-  const windowsCallback = process.platform === 'win32' ? 'node ' : '';
-  execSync(`${windowsCallback}${sentryCliBin} sourcemaps upload ${isHermes ? '--debug-id-reference' : ''} ${assets.join(' ')}`, {
+
+  // Build arguments array for spawnSync (no shell interpretation needed)
+  const args = ['sourcemaps', 'upload'];
+  if (isHermes) {
+    args.push('--debug-id-reference');
+  }
+  args.push(...assets);
+
+  const result = spawnSync(sentryCliBin, args, {
     env: {
       ...process.env,
       [SENTRY_PROJECT]: sentryProject,
@@ -227,6 +237,15 @@ for (const [assetGroupName, assets] of Object.entries(groupedAssets)) {
     },
     stdio: 'inherit',
   });
+
+  if (result.error) {
+    console.error('Failed to upload sourcemaps:', result.error);
+    process.exit(1);
+  }
+  if (result.status !== 0) {
+    console.error(`sentry-cli exited with status ${result.status}`);
+    process.exit(result.status);
+  }
   numAssetsUploaded++;
 }
 
diff --git a/packages/core/test/scripts/expo-upload-sourcemaps.test.ts b/packages/core/test/scripts/expo-upload-sourcemaps.test.ts
new file mode 100644
index 0000000000..1c2791452f
--- /dev/null
+++ b/packages/core/test/scripts/expo-upload-sourcemaps.test.ts
@@ -0,0 +1,313 @@
+import { spawnSync } from 'child_process';
+import * as fs from 'fs';
+import * as os from 'os';
+import * as path from 'path';
+
+const SCRIPTS_DIR = path.resolve(__dirname, '../../scripts');
+const EXPO_UPLOAD_SCRIPT = path.join(SCRIPTS_DIR, 'expo-upload-sourcemaps.js');
+
+describe('expo-upload-sourcemaps.js', () => {
+  let tempDir: string;
+  let outputDir: string;
+  let mockSentryCliScript: string;
+
+  beforeEach(() => {
+    // Create temporary directories for test artifacts
+    tempDir = fs.mkdtempSync(path.join(os.tmpdir(), 'expo-upload-test-'));
+    outputDir = path.join(tempDir, 'dist');
+    fs.mkdirSync(outputDir, { recursive: true });
+
+    // Create a mock sentry-cli script
+    mockSentryCliScript = path.join(tempDir, 'mock-sentry-cli');
+    const mockCliContent = `#!/usr/bin/env node
+const args = process.argv.slice(2);
+const output = process.env.MOCK_CLI_OUTPUT || 'Mock upload successful';
+
+// Echo the arguments to verify they're passed correctly
+console.log('Arguments received:', JSON.stringify(args));
+console.log(output);
+
+const exitCode = parseInt(process.env.MOCK_CLI_EXIT_CODE || '0');
+process.exit(exitCode);
+`;
+    fs.writeFileSync(mockSentryCliScript, mockCliContent);
+    fs.chmodSync(mockSentryCliScript, '755');
+  });
+
+  afterEach(() => {
+    // Clean up temp directory
+    if (tempDir && fs.existsSync(tempDir)) {
+      fs.rmSync(tempDir, { recursive: true, force: true });
+    }
+  });
+
+  const createAssets = (filenames: string[]) => {
+    filenames.forEach(filename => {
+      const filePath = path.join(outputDir, filename);
+      if (filename.endsWith('.map')) {
+        // Create a valid sourcemap with debug_id
+        fs.writeFileSync(
+          filePath,
+          JSON.stringify({
+            version: 3,
+            sources: ['index.js'],
+            names: [],
+            mappings: 'AAAA',
+            debugId: 'test-debug-id-123',
+          }),
+        );
+      } else {
+        // Create a simple JS file
+        fs.writeFileSync(filePath, '// Mock bundle file');
+      }
+    });
+  };
+
+  const runScript = (env: Record<string, string> = {}): { stdout: string; stderr: string; exitCode: number } => {
+    const defaultEnv = {
+      SENTRY_ORG: 'test-org',
+      SENTRY_PROJECT: 'test-project',
+      SENTRY_URL: 'https://sentry.io/',
+      SENTRY_AUTH_TOKEN: 'test-token',
+      SENTRY_CLI_EXECUTABLE: mockSentryCliScript,
+      // Skip expo config loading
+      EXPO_PUBLIC_SKIP_CONFIG: 'true',
+    };
+
+    try {
+      const result = spawnSync(process.execPath, [EXPO_UPLOAD_SCRIPT, outputDir], {
+        env: { ...process.env, ...defaultEnv, ...env },
+        encoding: 'utf8',
+      });
+
+      return {
+        stdout: result.stdout || '',
+        stderr: result.stderr || '',
+        exitCode: result.status || 0,
+      };
+    } catch (error: any) {
+      return {
+        stdout: error.stdout?.toString() || '',
+        stderr: error.stderr?.toString() || '',
+        exitCode: error.status || 1,
+      };
+    }
+  };
+
+  describe('basic functionality', () => {
+    it('successfully uploads normal bundles and sourcemaps', () => {
+      createAssets(['bundle.js', 'bundle.js.map']);
+
+      const result = runScript({
+        MOCK_CLI_EXIT_CODE: '0',
+        MOCK_CLI_OUTPUT: 'Upload successful',
+      });
+
+      expect(result.exitCode).toBe(0);
+      expect(result.stdout).toContain('Upload successful');
+      expect(result.stdout).toContain('Uploaded bundles and sourcemaps to Sentry successfully');
+    });
+
+    it('handles multiple bundles', () => {
+      createAssets(['bundle1.js', 'bundle1.js.map', 'bundle2.js', 'bundle2.js.map']);
+
+      const result = runScript({
+        MOCK_CLI_EXIT_CODE: '0',
+      });
+
+      expect(result.exitCode).toBe(0);
+      expect(result.stdout).toContain('Uploaded bundles and sourcemaps to Sentry successfully');
+    });
+
+    it('skips bundles without sourcemaps', () => {
+      createAssets(['bundle.js']); // No .map file
+
+      const result = runScript({
+        MOCK_CLI_EXIT_CODE: '0',
+      });
+
+      expect(result.exitCode).toBe(0);
+      expect(result.stdout).toContain('Sourcemap for');
+      expect(result.stdout).toContain('not found, skipping');
+    });
+
+    it('exits with error when sentry-cli fails', () => {
+      createAssets(['bundle.js', 'bundle.js.map']);
+
+      const result = runScript({
+        MOCK_CLI_EXIT_CODE: '1',
+        MOCK_CLI_OUTPUT: 'Upload failed: Network error',
+      });
+
+      expect(result.exitCode).toBe(1);
+      expect(result.stdout).toContain('Upload failed: Network error');
+    });
+  });
+
+  describe('security: command injection prevention', () => {
+    it('safely handles filenames with spaces (simulating special characters)', () => {
+      // Use spaces to simulate special character handling
+      // (semicolons, pipes can't be created on most filesystems)
+      const fileWithSpaces = 'bundle with spaces.js';
+      const mapWithSpaces = 'bundle with spaces.js.map';
+
+      createAssets([fileWithSpaces, mapWithSpaces]);
+
+      const result = runScript({
+        MOCK_CLI_EXIT_CODE: '0',
+      });
+
+      // Should complete successfully with proper argument passing
+      expect(result.exitCode).toBe(0);
+      expect(result.stdout).toContain('Arguments received:');
+      const argsMatch = result.stdout.match(/Arguments received: (.+)/);
+      if (argsMatch) {
+        const args = JSON.parse(argsMatch[1]);
+        // Verify filename with spaces is passed as single argument
+        const fileArg = args.find((arg: string) => arg.includes('bundle with spaces'));
+        expect(fileArg).toBeDefined();
+        expect(fileArg).toContain('bundle with spaces.js');
+      }
+    });
+
+    it('safely handles filenames with shell metacharacters via spawnSync', () => {
+      // spawnSync doesn't use a shell, so no special character escaping is needed
+      // Test with parentheses which are valid in filenames but special to shell
+      const fileWithParens = 'bundle(test).js';
+      const mapWithParens = 'bundle(test).js.map';
+
+      createAssets([fileWithParens, mapWithParens]);
+
+      const result = runScript({
+        MOCK_CLI_EXIT_CODE: '0',
+      });
+
+      expect(result.exitCode).toBe(0);
+      expect(result.stdout).toContain('Arguments received:');
+      // Verify parentheses are preserved
+      const argsMatch = result.stdout.match(/Arguments received: (.+)/);
+      if (argsMatch) {
+        const args = JSON.parse(argsMatch[1]);
+        const fileArg = args.find((arg: string) => arg.includes('(test)'));
+        expect(fileArg).toBeDefined();
+      }
+    });
+
+    it('demonstrates shell safety: no command interpretation possible', () => {
+      // This test verifies that spawnSync passes arguments directly
+      // without shell interpretation, making command injection impossible
+      const normalFile = 'bundle-safe.js';
+      const normalMap = 'bundle-safe.js.map';
+
+      createAssets([normalFile, normalMap]);
+
+      const result = runScript({
+        MOCK_CLI_EXIT_CODE: '0',
+      });
+
+      expect(result.exitCode).toBe(0);
+      // Verify arguments are passed as an array
+      const argsMatch = result.stdout.match(/Arguments received: (.+)/);
+      if (argsMatch) {
+        const args = JSON.parse(argsMatch[1]);
+        // First arg should be the subcommand
+        expect(args[0]).toBe('sourcemaps');
+        expect(args[1]).toBe('upload');
+        // Remaining args should be file paths
+        expect(args.length).toBeGreaterThanOrEqual(2);
+      }
+    });
+  });
+
+  describe('Hermes support', () => {
+    it('passes --debug-id-reference flag for Hermes bundles', () => {
+      // For Hermes, we need the .hbc and .hbc.map files
+      createAssets(['bundle.hbc', 'bundle.hbc.map']);
+
+      const result = runScript({
+        MOCK_CLI_EXIT_CODE: '0',
+      });
+
+      expect(result.exitCode).toBe(0);
+      // Check that the flag is in the arguments
+      const argsMatch = result.stdout.match(/Arguments received: (.+)/);
+      if (argsMatch) {
+        const args = JSON.parse(argsMatch[1]);
+        expect(args).toContain('--debug-id-reference');
+      }
+    });
+
+    it('does not pass --debug-id-reference flag for non-Hermes bundles', () => {
+      createAssets(['bundle.js', 'bundle.js.map']);
+
+      const result = runScript({
+        MOCK_CLI_EXIT_CODE: '0',
+      });
+
+      expect(result.exitCode).toBe(0);
+      const argsMatch = result.stdout.match(/Arguments received: (.+)/);
+      if (argsMatch) {
+        const args = JSON.parse(argsMatch[1]);
+        expect(args).not.toContain('--debug-id-reference');
+      }
+    });
+  });
+
+  describe('environment variables', () => {
+    it('requires SENTRY_AUTH_TOKEN', () => {
+      createAssets(['bundle.js', 'bundle.js.map']);
+
+      const result = spawnSync(process.execPath, [EXPO_UPLOAD_SCRIPT, outputDir], {
+        env: {
+          ...process.env,
+          SENTRY_ORG: 'test-org',
+          SENTRY_PROJECT: 'test-project',
+          SENTRY_URL: 'https://sentry.io/',
+          SENTRY_CLI_EXECUTABLE: mockSentryCliScript,
+          // Explicitly unset SENTRY_AUTH_TOKEN
+          SENTRY_AUTH_TOKEN: undefined,
+        },
+        encoding: 'utf8',
+      });
+
+      expect(result.status).toBe(1);
+      expect(result.stdout || result.stderr).toContain('SENTRY_AUTH_TOKEN environment variable must be set');
+    });
+
+    it('requires output directory argument', () => {
+      const result = spawnSync(process.execPath, [EXPO_UPLOAD_SCRIPT], {
+        env: {
+          ...process.env,
+          SENTRY_ORG: 'test-org',
+          SENTRY_PROJECT: 'test-project',
+          SENTRY_URL: 'https://sentry.io/',
+          SENTRY_AUTH_TOKEN: 'test-token',
+          SENTRY_CLI_EXECUTABLE: mockSentryCliScript,
+        },
+        encoding: 'utf8',
+        timeout: 5000, // Add timeout in case expo config hangs
+      });
+
+      expect(result.status).toBe(1);
+      const output = result.stdout + result.stderr;
+      expect(output).toContain('Provide the directory with your bundles and sourcemaps');
+    });
+  });
+
+  describe('sourcemap processing', () => {
+    it('converts debugId to debug_id in sourcemaps', () => {
+      createAssets(['bundle.js', 'bundle.js.map']);
+
+      runScript({
+        MOCK_CLI_EXIT_CODE: '0',
+      });
+
+      // Read the sourcemap file to verify it was updated
+      const sourceMapPath = path.join(outputDir, 'bundle.js.map');
+      const sourceMapContent = JSON.parse(fs.readFileSync(sourceMapPath, 'utf8'));
+
+      expect(sourceMapContent.debug_id).toBe('test-debug-id-123');
+      expect(sourceMapContent.debugId).toBe('test-debug-id-123');
+    });
+  });
+});