diff --git a/csreview/src/detector.js b/csreview/src/detector.js
index 473c11d..dae3a22 100644
--- a/csreview/src/detector.js
+++ b/csreview/src/detector.js
@@ -851,7 +851,11 @@ const VULNERABILITY_PATTERNS = [
     category: 'Configuration',
     name: 'Default Credentials',
     description: 'Default admin/password credentials.',
-    regex: /(?:admin|root|default|test)['"]?\s*[:=]\s*['"](?:admin|password|123456|root|default|changeme|test)['"]/gi,
+    // Requires a credential-context KEY (password/pwd/secret/credential) set to a
+    // weak/default value — not a bare admin|root|default|test key, which matched
+    // UI role-label maps like `{ admin: 'Admin' }` (a CRITICAL false positive).
+    regex:
+      /(?:pass(?:word|wd)?|pwd|secret|credential)['"]?\s*[:=]\s*['"](?:admin|password|123456|root|default|changeme|test|pass|secret|letmein|qwerty|admin123|password1|password123)['"]/gi,
     cwe: 'CWE-798',
     owasp: 'A07:2021-Identification and Authentication Failures',
     fix: 'Change all default credentials.',
diff --git a/csreview/src/ignore.js b/csreview/src/ignore.js
index 5d7b15b..b520220 100644
--- a/csreview/src/ignore.js
+++ b/csreview/src/ignore.js
@@ -219,6 +219,18 @@ export const DEFAULT_IGNORE_DIRS = [
   '.dart_tool', // Flutter/Dart build cache
   '.gradle', // Gradle/Android cache
   '.supabase', // Supabase CLI local runtime state (distinct from the `supabase/` source tree)
+  // JS/TS framework build outputs & deploy/cache dirs — compiled/bundled code,
+  // never first-party source. `.output` (Nuxt/Nitro) was the dominant false-
+  // positive source on a real monorepo: prototype-pollution in `_nitro.mjs`,
+  // JWTs in bundles, etc. (`.next`/`.nuxt` were already covered above.)
+  '.output', // Nuxt/Nitro build output
+  'out', // Next.js static export
+  '.vercel', // Vercel build output
+  '.netlify', // Netlify build output
+  '.svelte-kit', // SvelteKit build output
+  '.angular', // Angular cache/build
+  '.turbo', // Turborepo cache
+  '.parcel-cache', // Parcel cache
 ];
 
 /** Built-in default file globs (minified/generated artifacts and prior reports). */
diff --git a/csreview/src/index.js b/csreview/src/index.js
index 601f997..7201234 100644
--- a/csreview/src/index.js
+++ b/csreview/src/index.js
@@ -10,7 +10,13 @@ import { generateMarkdownReport } from './reports/markdown.js';
 import { generateSarifReport } from './reports/sarif.js';
 import { calculateSecurityScore } from './score.js';
 import { normalizeLocalPath, safeResolveInside } from './pathSafety.js';
-import { loadIgnore, applyIgnore, compileIgnorePatterns, DEFAULT_IGNORE_PATTERNS } from './ignore.js';
+import {
+  loadIgnore,
+  applyIgnore,
+  compileIgnorePatterns,
+  DEFAULT_IGNORE_PATTERNS,
+  DEFAULT_IGNORE_DIRS,
+} from './ignore.js';
 import { loadBaseline, applyBaseline, writeBaseline } from './baseline.js';
 
 /**
@@ -865,12 +871,26 @@ export function normalizeOsvScannerFindings(osvJson = {}, rootDir = process.cwd(
   return findings;
 }
 
+/**
+ * Build Semgrep `--exclude <dir>` argument pairs from the canonical ignore-dir
+ * list so Semgrep skips the SAME build outputs / vendored dirs as the heuristic
+ * detector. Without this Semgrep scanned `.output`, `dist`, `.nuxt`, etc. and
+ * produced critical false positives from compiled bundles (e.g. prototype
+ * pollution in `_nitro.mjs`).
+ *
+ * @param {string[]} [dirs]
+ * @returns {string[]}
+ */
+export function semgrepExcludeArgs(dirs = DEFAULT_IGNORE_DIRS) {
+  return dirs.flatMap((dir) => ['--exclude', dir]);
+}
+
 async function runSemgrep(rootDir) {
   try {
     const versionResult = await execTool('semgrep', ['--version'], { timeout: VERSION_CHECK_TIMEOUT_MS });
     const scanResult = await execTool(
       'semgrep',
-      ['--config', 'auto', '--json', '--quiet', '--exclude', 'node_modules', '--exclude', 'csreview-reports', rootDir],
+      ['--config', 'auto', '--json', '--quiet', ...semgrepExcludeArgs(), rootDir],
       {
         cwd: rootDir,
         timeout: 120000,
diff --git a/csreview/test/detector-calibration.test.js b/csreview/test/detector-calibration.test.js
index 02ee99d..1bfe3ab 100644
--- a/csreview/test/detector-calibration.test.js
+++ b/csreview/test/detector-calibration.test.js
@@ -87,6 +87,25 @@ test('findings in non-source paths (test/fixtures) are downgraded; real source k
   assert.equal(inTest.confidence, 'LOW');
 });
 
+test('DEFAULT_CREDENTIALS does not fire on UI role-label maps but still catches weak password defaults', () => {
+  // FP (DeckMidia): a role->label map like { admin: 'Admin' } was flagged as
+  // CRITICAL Default Credentials because the rule matched admin: 'Admin'.
+  const fp = scan([
+    { path: 'src/labels.js', code: "export const roleLabels = { owner: 'Owner', admin: 'Admin', test: 'Test' };\n" },
+  ]);
+  assert.equal(
+    fp.filter((f) => String(f.id).startsWith('DEFAULT_CREDENTIALS')).length,
+    0,
+    `unexpected DEFAULT_CREDENTIALS FPs: ${fp.map((f) => f.file).join(', ')}`,
+  );
+  // TP: a credential field set to a weak/default value must still be caught.
+  const tp = scan([{ path: 'src/cfg.js', code: "export const cfg = { password: 'admin', pwd: 'changeme' };\n" }]);
+  assert.ok(
+    tp.some((f) => String(f.id).startsWith('DEFAULT_CREDENTIALS')),
+    'expected DEFAULT_CREDENTIALS to catch password: "admin"',
+  );
+});
+
 test('the shipped .csreview-ignore keeps a csreview self-audit free of rule-definition meta-FPs', async () => {
   // A scanner must not flag its own rulebook: detector.js (regexes/descriptions/
   // exploitation strings) and dumpGuide.js (sample connection strings) match the
diff --git a/csreview/test/ignore.test.js b/csreview/test/ignore.test.js
index f894ddb..5567ccd 100644
--- a/csreview/test/ignore.test.js
+++ b/csreview/test/ignore.test.js
@@ -129,6 +129,8 @@ test('DEFAULT_IGNORE_DIRS covers vendored deps, build output, and generated cach
     '.dart_tool', // Flutter/Dart cache (the dominant external-tool noise source)
     '.gradle', // Gradle/Android cache
     '.supabase', // Supabase CLI local runtime state
+    '.output', // Nuxt/Nitro build output (the DeckMidia .output false-positive source)
+    'out', // Next.js static export
     'csreview-reports',
     '.csreview',
   ]) {
@@ -142,6 +144,9 @@ test('DEFAULT_IGNORE_PATTERNS are gitignore-syntax and scope external-tool findi
   assert.ok(isIgnored('flutter/apps/operator/.dart_tool/chrome-device/Default/Preferences', compiled));
   assert.ok(isIgnored('supabase-stuff/.supabase/postgres/data/x', compiled));
   assert.ok(isIgnored('android/app/.gradle/cache/x', compiled));
+  // Nuxt/Nitro build output — the DeckMidia false positives (prototype pollution
+  // in _nitro.mjs, JWT in bundles) all came from here.
+  assert.ok(isIgnored('apps/web/.output/server/chunks/_nitro.mjs', compiled));
   assert.ok(isIgnored('a/node_modules/pkg/index.js', compiled));
   assert.ok(isIgnored('packages/web/dist/bundle.min.js', compiled));
   // root-level cache dirs (no parent component) must also match — guards against
diff --git a/csreview/test/tool-env.test.js b/csreview/test/tool-env.test.js
index 1e6e51d..4d6a0a6 100644
--- a/csreview/test/tool-env.test.js
+++ b/csreview/test/tool-env.test.js
@@ -1,7 +1,7 @@
 // @ts-check
 import test from 'node:test';
 import assert from 'node:assert/strict';
-import { withToolEnv } from '../src/index.js';
+import { withToolEnv, semgrepExcludeArgs } from '../src/index.js';
 
 // Semgrep's update/version "phone home" check can hang the process (notably on
 // Linux): `semgrep --version` prints the version then blocks on the check.
@@ -32,3 +32,17 @@ test('withToolEnv is a no-op for non-semgrep tools (returns options unchanged)',
   assert.equal(opts, original);
   assert.equal(opts.env, undefined);
 });
+
+test('semgrepExcludeArgs excludes build outputs and vendored dirs (the DeckMidia .output noise)', () => {
+  const args = semgrepExcludeArgs();
+  // shape: alternating --exclude <dir>
+  assert.ok(args.length >= 2 && args.length % 2 === 0);
+  const excluded = new Set();
+  for (let i = 0; i < args.length; i += 2) {
+    assert.equal(args[i], '--exclude');
+    excluded.add(args[i + 1]);
+  }
+  for (const dir of ['node_modules', 'dist', 'build', '.nuxt', '.output', 'csreview-reports', '.git']) {
+    assert.ok(excluded.has(dir), `semgrep must exclude ${dir}`);
+  }
+});