diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5993e3634..6c2ff8519 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 ### Changed
 - **Bazel diagnostics** — `socket manifest bazel --verbose` now emits bounded subprocess traces with argv, cwd, duration, exit status, output sizes, and failure stderr tails to make customer log-only triage safer and faster.
 
+## [1.1.104](https://github.com/SocketDev/socket-cli/releases/tag/v1.1.104) - 2026-05-26
+
+### Fixed
+- Coana CLI invocation: strip `npm_package_*` env vars before spawning the npm-install fallback. Prevents `spawn E2BIG` failures in large monorepos where the parent process has hundreds of `npm_package_*` env vars populated from the root `package.json`. Preserves `npm_config_*` (registry / proxy / cache from `.npmrc`).
+
 ## [1.1.103](https://github.com/SocketDev/socket-cli/releases/tag/v1.1.103) - 2026-05-26
 
 ### Changed
diff --git a/package.json b/package.json
index 80cd5aa37..eb82d5031 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "socket",
-  "version": "1.1.103",
+  "version": "1.1.104",
   "description": "CLI for Socket.dev",
   "homepage": "https://github.com/SocketDev/socket-cli",
   "license": "MIT AND OFL-1.1",
diff --git a/src/utils/dlx.mts b/src/utils/dlx.mts
index e30a6d3ff..4328a0e8c 100644
--- a/src/utils/dlx.mts
+++ b/src/utils/dlx.mts
@@ -193,6 +193,32 @@ export type CoanaDlxOptions = DlxOptions & {
  */
 const installedCoanaScriptPathsByVersion = new Map<string, string>()
 
+/**
+ * Strip npm-injected `npm_package_*` env vars before spawning a Coana
+ * subprocess. npm (and pnpm/yarn classic) populate one env var per leaf in
+ * the cwd's package.json — `npm_package_dependencies_*`, `npm_package_scripts_*`,
+ * etc. In big monorepos with hundreds of deps this can easily account for
+ * 50KB+ of environment, pushing combined argv + env past Linux ARG_MAX
+ * (~128KB) and causing `spawn` to fail with E2BIG before Coana even starts.
+ *
+ * Coana does not read `npm_package_*` itself, so dropping them is safe. We
+ * intentionally keep `npm_config_*` (registry, cache, proxy settings sourced
+ * from .npmrc), `npm_lifecycle_*`, and everything else untouched — those can
+ * matter for outbound network behavior of nested `npm install` calls.
+ */
+function sanitizeEnvForCoanaSubprocess(
+  env: NodeJS.ProcessEnv,
+): NodeJS.ProcessEnv {
+  const out: NodeJS.ProcessEnv = {}
+  for (const key of Object.keys(env)) {
+    if (key.startsWith('npm_package_')) {
+      continue
+    }
+    out[key] = env[key]
+  }
+  return out
+}
+
 /**
  * Spawn an installed Coana entry point via `node` (or directly, if it's a
  * native binary). Shared by the SOCKET_CLI_COANA_LOCAL_PATH branch and the
@@ -210,7 +236,7 @@ async function spawnCoanaScriptViaNode(
   const spawnArgs = isBinary ? args : [scriptPath, ...args]
   const spawnResult = await spawn(isBinary ? scriptPath : 'node', spawnArgs, {
     cwd: options.cwd,
-    env: finalEnv,
+    env: sanitizeEnvForCoanaSubprocess(finalEnv),
     stdio: spawnExtra?.['stdio'] || 'inherit',
   })
 
@@ -278,7 +304,7 @@ async function installCoanaToTmpdir(
       `@coana-tech/cli@${version}`,
     ],
     {
-      env: finalEnv,
+      env: sanitizeEnvForCoanaSubprocess(finalEnv),
       stdio: 'inherit',
     },
   )
diff --git a/src/utils/dlx.test.mts b/src/utils/dlx.test.mts
index 44bd32a2a..ce4e59a91 100644
--- a/src/utils/dlx.test.mts
+++ b/src/utils/dlx.test.mts
@@ -468,5 +468,54 @@ describe('utils/dlx', () => {
       )
       expect(npmInstallCalls).toHaveLength(1)
     })
+
+    it('strips npm_package_* env vars in the fallback to avoid E2BIG in big monorepos', async () => {
+      // Simulate a parent env polluted with npm_package_* (as set by npm/pnpm
+      // when running inside a project with a populated package.json). The
+      // fallback must not pass these through to its npm install or node
+      // spawns, or the same ARG_MAX overflow that broke the dlx path would
+      // recur.
+      process.env['npm_package_name'] = 'forge'
+      process.env['npm_package_dependencies_react'] = '^18.2.0'
+      process.env['npm_package_devDependencies_typescript'] = '^5.0.0'
+      // npm_config_* must be preserved — these carry registry/proxy settings
+      // sourced from .npmrc and are needed for the nested npm install.
+      process.env['npm_config_registry'] = 'https://artifactory.example/npm/'
+
+      try {
+        const result = await spawnCoanaDlx(['run', '.'], 'acme', {
+          coanaVersion: nextVersion(),
+        })
+        expect(result.ok).toBe(true)
+
+        const npmInstallCall = mockSpawn.mock.calls.find(
+          ([cmd, args]) => cmd === 'npm' && (args as string[])[0] === 'install',
+        )!
+        const nodeCall = mockSpawn.mock.calls.find(([cmd]) => cmd === 'node')!
+
+        const npmEnv = (npmInstallCall[2] as { env: NodeJS.ProcessEnv }).env
+        const nodeEnv = (nodeCall[2] as { env: NodeJS.ProcessEnv }).env
+
+        // npm_package_* are stripped from both spawns.
+        expect(npmEnv['npm_package_name']).toBeUndefined()
+        expect(npmEnv['npm_package_dependencies_react']).toBeUndefined()
+        expect(npmEnv['npm_package_devDependencies_typescript']).toBeUndefined()
+        expect(nodeEnv['npm_package_name']).toBeUndefined()
+        expect(nodeEnv['npm_package_dependencies_react']).toBeUndefined()
+
+        // npm_config_* is preserved (registry override survives).
+        expect(npmEnv['npm_config_registry']).toBe(
+          'https://artifactory.example/npm/',
+        )
+        expect(nodeEnv['npm_config_registry']).toBe(
+          'https://artifactory.example/npm/',
+        )
+      } finally {
+        delete process.env['npm_package_name']
+        delete process.env['npm_package_dependencies_react']
+        delete process.env['npm_package_devDependencies_typescript']
+        delete process.env['npm_config_registry']
+      }
+    })
   })
 })