@@ -45,6 +45,7 @@ class CliConfig:
     files: str = None
     ignore_commit_files: bool = False
     disable_blocking: bool = False
+    strict_blocking: bool = False
     integration_type: IntegrationType = "api"
     integration_org_slug: Optional[str] = None
     pending_head: bool = False
@@ -123,6 +124,7 @@ def from_args(cls, args_list: Optional[List[str]] = None) -> 'CliConfig':
             'files': args.files,
             'ignore_commit_files': args.ignore_commit_files,
             'disable_blocking': args.disable_blocking,
+            'strict_blocking': args.strict_blocking,
             'integration_type': args.integration,
             'pending_head': args.pending_head,
             'timeout': args.timeout,
@@ -523,6 +525,12 @@ def create_argument_parser() -> argparse.ArgumentParser:
         action="store_true",
         help=argparse.SUPPRESS
     )
+    advanced_group.add_argument(
+        "--strict-blocking",
+        dest="strict_blocking",
+        action="store_true",
+        help="Fail on ANY security policy violations (blocking severity), not just new ones. Only works in diff mode."
+    )
     advanced_group.add_argument(
         "--enable-diff",
         dest="enable_diff",
 
@@ -1091,7 +1091,13 @@ def create_new_diff(
             packages
         ) = self.get_added_and_removed_packages(head_full_scan_id, new_full_scan.id)
 
-        diff = self.create_diff_report(added_packages, removed_packages)
+        # Separate unchanged packages from added/removed for --strict-blocking support
+        unchanged_packages = {
+            pkg_id: pkg for pkg_id, pkg in packages.items()
+            if pkg_id not in added_packages and pkg_id not in removed_packages
+        }
+
+        diff = self.create_diff_report(added_packages, removed_packages, unchanged_packages)
         diff.packages = packages
 
         base_socket = "https://socket.dev/dashboard/org"
@@ -1114,6 +1120,7 @@ def create_diff_report(
         self,
         added_packages: Dict[str, Package],
         removed_packages: Dict[str, Package],
+        unchanged_packages: Optional[Dict[str, Package]] = None,
         direct_only: bool = True
     ) -> Diff:
         """
@@ -1123,10 +1130,12 @@ def create_diff_report(
         1. Records new/removed packages (direct only by default)
         2. Collects alerts from both sets of packages
         3. Determines new capabilities introduced
+        4. Optionally collects alerts from unchanged packages for --strict-blocking
 
         Args:
             added_packages: Dict of packages added in new scan
             removed_packages: Dict of packages removed in new scan
+            unchanged_packages: Dict of packages that didn't change (for --strict-blocking)
             direct_only: If True, only direct dependencies are included in new/removed lists
                         (but alerts are still processed for all packages)
 
@@ -1137,6 +1146,7 @@ def create_diff_report(
 
         alerts_in_added_packages: Dict[str, List[Issue]] = {}
         alerts_in_removed_packages: Dict[str, List[Issue]] = {}
+        alerts_in_unchanged_packages: Dict[str, List[Issue]] = {}
 
         seen_new_packages = set()
         seen_removed_packages = set()
@@ -1169,11 +1179,34 @@ def create_diff_report(
                 packages=removed_packages
             )
 
+        # Process unchanged packages for --strict-blocking support
+        if unchanged_packages:
+            for package_id, package in unchanged_packages.items():
+                # Skip packages that are in added or removed (they're already processed)
+                if package_id in added_packages or package_id in removed_packages:
+                    continue
+
+                self.add_package_alerts_to_collection(
+                    package=package,
+                    alerts_collection=alerts_in_unchanged_packages,
+                    packages=unchanged_packages
+                )
+
         diff.new_alerts = Core.get_new_alerts(
             alerts_in_added_packages,
             alerts_in_removed_packages
         )
 
+        # Get unchanged alerts (for --strict-blocking mode)
+        diff.unchanged_alerts = Core.get_unchanged_alerts(
+            alerts_in_unchanged_packages
+        )
+
+        # Get removed alerts (for completeness)
+        diff.removed_alerts = Core.get_removed_alerts(
+            alerts_in_removed_packages
+        )
+
         diff.new_capabilities = Core.get_capabilities_for_added_packages(added_packages)
 
         Core.add_purl_capabilities(diff)
@@ -1433,3 +1466,62 @@ def get_new_alerts(
                             consolidated_alerts.add(alert_str)
 
         return alerts
+
+    @staticmethod
+    def get_unchanged_alerts(
+        unchanged_package_alerts: Dict[str, List[Issue]]
+    ) -> List[Issue]:
+        """
+        Extract all alerts from unchanged packages that are errors or warnings.
+
+        This is used for --strict-blocking mode to identify existing violations
+        that should cause builds to fail.
+
+        Args:
+            unchanged_package_alerts: Dictionary of alerts from packages that didn't change
+
+        Returns:
+            List of all error/warning alerts from unchanged packages
+        """
+        alerts: List[Issue] = []
+        consolidated_alerts = set()
+
+        for alert_key in unchanged_package_alerts:
+            for alert in unchanged_package_alerts[alert_key]:
+                # Consolidate by package and alert type
+                alert_str = f"{alert.purl},{alert.type}"
+
+                # Only include error or warning alerts
+                if (alert.error or alert.warn) and alert_str not in consolidated_alerts:
+                    alerts.append(alert)
+                    consolidated_alerts.add(alert_str)
+
+        return alerts
+
+    @staticmethod
+    def get_removed_alerts(
+        removed_package_alerts: Dict[str, List[Issue]]
+    ) -> List[Issue]:
+        """
+        Extract all alerts from removed packages.
+
+        This is mainly for informational purposes - to show alerts that were removed.
+
+        Args:
+            removed_package_alerts: Dictionary of alerts from packages that were removed
+
+        Returns:
+            List of all alerts from removed packages
+        """
+        alerts: List[Issue] = []
+        consolidated_alerts = set()
+
+        for alert_key in removed_package_alerts:
+            for alert in removed_package_alerts[alert_key]:
+                alert_str = f"{alert.purl},{alert.type}"
+
+                if alert_str not in consolidated_alerts:
+                    alerts.append(alert)
+                    consolidated_alerts.add(alert_str)
+
+        return alerts
@@ -474,6 +474,8 @@ class Diff:
     packages: dict[str, Package]
     new_capabilities: Dict[str, List[str]]
     new_alerts: list[Issue]
+    unchanged_alerts: list[Issue]
+    removed_alerts: list[Issue]
     id: str
     sbom: str
     report_url: str
@@ -490,6 +492,10 @@ def __init__(self, **kwargs):
             self.removed_packages = []
         if not hasattr(self, "new_alerts"):
             self.new_alerts = []
+        if not hasattr(self, "unchanged_alerts"):
+            self.unchanged_alerts = []
+        if not hasattr(self, "removed_alerts"):
+            self.removed_alerts = []
         if not hasattr(self, "new_capabilities"):
             self.new_capabilities = {}
 
@@ -508,6 +514,8 @@ def to_dict(self) -> dict:
             "new_capabilities": self.new_capabilities,
             "removed_packages": [p.to_dict() for p in self.removed_packages],
             "new_alerts": [alert.__dict__ for alert in self.new_alerts],
+            "unchanged_alerts": [alert.__dict__ for alert in self.unchanged_alerts] if hasattr(self, "unchanged_alerts") else [],
+            "removed_alerts": [alert.__dict__ for alert in self.removed_alerts] if hasattr(self, "removed_alerts") else [],
             "id": self.id,
             "sbom": self.sbom if hasattr(self, "sbom") else [],
             "packages": {k: v.to_dict() for k, v in self.packages.items()} if hasattr(self, "packages") else {},
 
@@ -77,12 +77,40 @@ def return_exit_code(self, diff_report: Diff) -> int:
 
     def output_console_comments(self, diff_report: Diff, sbom_file_name: Optional[str] = None) -> None:
         """Outputs formatted console comments"""
-        if len(diff_report.new_alerts) == 0:
+        has_new_alerts = len(diff_report.new_alerts) > 0
+        has_unchanged_alerts = (
+            self.config.strict_blocking and
+            hasattr(diff_report, 'unchanged_alerts') and
+            len(diff_report.unchanged_alerts) > 0
+        )
+
+        if not has_new_alerts and not has_unchanged_alerts:
             self.logger.info("No issues found")
             return
 
+        # Count blocking vs warning alerts
+        new_blocking = sum(1 for issue in diff_report.new_alerts if issue.error)
+        new_warning = sum(1 for issue in diff_report.new_alerts if issue.warn)
+
+        unchanged_blocking = 0
+        unchanged_warning = 0
+        if has_unchanged_alerts:
+            unchanged_blocking = sum(1 for issue in diff_report.unchanged_alerts if issue.error)
+            unchanged_warning = sum(1 for issue in diff_report.unchanged_alerts if issue.warn)
+
         console_security_comment = Messages.create_console_security_alert_table(diff_report)
+
+        # Build status message
         self.logger.info("Security issues detected by Socket Security:")
+        if new_blocking > 0:
+            self.logger.info(f"  - NEW blocking issues: {new_blocking}")
+        if new_warning > 0:
+            self.logger.info(f"  - NEW warning issues: {new_warning}")
+        if unchanged_blocking > 0:
+            self.logger.info(f"  - EXISTING blocking issues: {unchanged_blocking} (causing failure due to --strict-blocking)")
+        if unchanged_warning > 0:
+            self.logger.info(f"  - EXISTING warning issues: {unchanged_warning}")
+
         self.logger.info(f"Diff Url: {diff_report.diff_url}")
         self.logger.info(f"\n{console_security_comment}")
 
@@ -105,13 +133,30 @@ def output_console_sarif(self, diff_report: Diff, sbom_file_name: Optional[str]
 
     def report_pass(self, diff_report: Diff) -> bool:
         """Determines if the report passes security checks"""
-        if not diff_report.new_alerts:
+        # Priority 1: --disable-blocking always passes
+        if self.config.disable_blocking:
             return True
 
-        if self.config.disable_blocking:
+        # Check new alerts for blocking issues
+        has_new_blocking_alerts = any(issue.error for issue in diff_report.new_alerts)
+
+        # Check unchanged alerts if --strict-blocking is enabled
+        has_unchanged_blocking_alerts = False
+        if self.config.strict_blocking and hasattr(diff_report, 'unchanged_alerts'):
+            has_unchanged_blocking_alerts = any(
+                issue.error for issue in diff_report.unchanged_alerts
+            )
+
+        # If no alerts at all, pass
+        if not diff_report.new_alerts and not (
+            self.config.strict_blocking and
+            hasattr(diff_report, 'unchanged_alerts') and
+            diff_report.unchanged_alerts
+        ):
             return True
 
-        return not any(issue.error for issue in diff_report.new_alerts)
+        # Fail if there are any blocking alerts (new or unchanged with --strict-blocking)
+        return not (has_new_blocking_alerts or has_unchanged_blocking_alerts)
 
     def save_sbom_file(self, diff_report: Diff, sbom_file_name: Optional[str] = None) -> None:
         """Saves SBOM file if filename is provided"""
 
@@ -49,7 +49,12 @@ def main_code():
     config = CliConfig.from_args()
     log.info(f"Starting Socket Security CLI version {config.version}")
     log.debug(f"config: {config.to_dict()}")
-    
+
+    # Warn if strict-blocking is used with disable-blocking
+    if config.strict_blocking and config.disable_blocking:
+        log.warning("Both --strict-blocking and --disable-blocking specified. "
+                   "--disable-blocking takes precedence and will always return exit code 0.")
+
     # Validate API token
     if not config.api_token:
         log.info("Socket API Token not found. Please set it using either:\n"
@@ -625,9 +630,13 @@ def main_code():
         core.save_file(config.license_file_name, json.dumps(all_packages))
 
     # If we forced API mode due to no supported files, behave as if --disable-blocking was set
-    if force_api_mode and not config.disable_blocking:
-        log.debug("Temporarily enabling disable_blocking due to no supported manifest files")
-        config.disable_blocking = True
+    if force_api_mode:
+        if config.strict_blocking:
+            log.warning("--strict-blocking is only supported in diff mode. "
+                       "API mode (no diff) cannot evaluate existing violations.")
+        if not config.disable_blocking:
+            log.debug("Temporarily enabling disable_blocking due to no supported manifest files")
+            config.disable_blocking = True
 
     sys.exit(output_handler.return_exit_code(diff))
 
 
@@ -0,0 +1,79 @@
+import pytest
+from socketsecurity.core import Core
+from socketsecurity.core.classes import Issue
+
+
+class TestDiffAlerts:
+    """Test alert collection for diff reports"""
+
+    def test_get_unchanged_alerts_filters_errors(self):
+        """Test that get_unchanged_alerts only returns error/warn alerts"""
+        alerts_dict = {
+            'alert1': [
+                Issue(error=True, warn=False, purl='npm/pkg1', type='malicious'),
+                Issue(error=False, warn=False, purl='npm/pkg1', type='info', monitor=True)
+            ],
+            'alert2': [
+                Issue(error=False, warn=True, purl='npm/pkg2', type='typosquat')
+            ]
+        }
+
+        result = Core.get_unchanged_alerts(alerts_dict)
+
+        # Should only include error=True and warn=True alerts
+        assert len(result) == 2
+        assert any(alert.error for alert in result)
+        assert any(alert.warn for alert in result)
+        assert not any(alert.monitor and not (alert.error or alert.warn) for alert in result)
+
+    def test_get_unchanged_alerts_deduplicates(self):
+        """Test that get_unchanged_alerts deduplicates by purl+type"""
+        alerts_dict = {
+            'alert1': [
+                Issue(error=True, warn=False, purl='npm/pkg1', type='malicious'),
+                Issue(error=True, warn=False, purl='npm/pkg1', type='malicious')  # Duplicate
+            ]
+        }
+
+        result = Core.get_unchanged_alerts(alerts_dict)
+
+        # Should deduplicate
+        assert len(result) == 1
+
+    def test_get_unchanged_alerts_empty(self):
+        """Test that get_unchanged_alerts handles empty input"""
+        result = Core.get_unchanged_alerts({})
+        assert len(result) == 0
+
+    def test_get_removed_alerts_all_alerts(self):
+        """Test that get_removed_alerts returns all alerts from removed packages"""
+        alerts_dict = {
+            'alert1': [
+                Issue(error=True, warn=False, purl='npm/pkg1', type='malicious'),
+                Issue(error=False, warn=True, purl='npm/pkg1', type='typosquat')
+            ]
+        }
+
+        result = Core.get_removed_alerts(alerts_dict)
+
+        # Should include all alerts, not just error/warn
+        assert len(result) == 2
+
+    def test_get_removed_alerts_deduplicates(self):
+        """Test that get_removed_alerts deduplicates by purl+type"""
+        alerts_dict = {
+            'alert1': [
+                Issue(error=True, warn=False, purl='npm/pkg1', type='malicious'),
+                Issue(error=True, warn=False, purl='npm/pkg1', type='malicious')  # Duplicate
+            ]
+        }
+
+        result = Core.get_removed_alerts(alerts_dict)
+
+        # Should deduplicate
+        assert len(result) == 1
+
+    def test_get_removed_alerts_empty(self):
+        """Test that get_removed_alerts handles empty input"""
+        result = Core.get_removed_alerts({})
+        assert len(result) == 0