diff --git a/dojo/tools/trivy/parser.py b/dojo/tools/trivy/parser.py
index fa41dd6c350..25746cd4089 100644
--- a/dojo/tools/trivy/parser.py
+++ b/dojo/tools/trivy/parser.py
@@ -344,7 +344,7 @@ def get_result_items(self, test, results, service_name=None, artifact_name=""):
                     service=service_name,
                     **status_fields,
                 )
-                finding.unsaved_tags = [vul_type, target_class]
+                finding.unsaved_tags = [tag for tag in (vul_type, target_class) if tag]
 
                 if vuln_id:
                     finding.unsaved_vulnerability_ids = [vuln_id]
@@ -405,7 +405,7 @@ def get_result_items(self, test, results, service_name=None, artifact_name=""):
                 if misc_avdid:
                     finding.unsaved_vulnerability_ids = []
                     finding.unsaved_vulnerability_ids.append(misc_avdid)
-                finding.unsaved_tags = [target_type, target_class]
+                finding.unsaved_tags = [tag for tag in (target_type, target_class) if tag]
                 items.append(finding)
 
             secrets = target_data.get("Secrets", [])
@@ -436,7 +436,7 @@ def get_result_items(self, test, results, service_name=None, artifact_name=""):
                     fix_available=True,
                     service=service_name,
                 )
-                finding.unsaved_tags = [target_class]
+                finding.unsaved_tags = [tag for tag in (target_class,) if tag]
                 items.append(finding)
 
             licenses = target_data.get("Licenses", [])
@@ -470,7 +470,7 @@ def get_result_items(self, test, results, service_name=None, artifact_name=""):
                     fix_available=True,
                     service=service_name,
                 )
-                finding.unsaved_tags = [target_class]
+                finding.unsaved_tags = [tag for tag in (target_class,) if tag]
                 items.append(finding)
 
         return items
diff --git a/dojo/validators.py b/dojo/validators.py
index 4c7c4f29d24..7c5bae5beea 100644
--- a/dojo/validators.py
+++ b/dojo/validators.py
@@ -38,8 +38,10 @@ def clean_tags(value: str | list[str], exception_class: Callable = ValidationErr
         return value
 
     if isinstance(value, list):
-        # Replace ALL occurrences of problematic characters in each tag
-        return [TAG_PATTERN.sub("_", tag) for tag in value]
+        # Replace ALL occurrences of problematic characters in each tag.
+        # Parsers can emit None tags (e.g. optional report fields); drop them
+        # instead of crashing the import pipeline (TypeError in re.sub).
+        return [TAG_PATTERN.sub("_", tag) for tag in value if tag is not None]
 
     if isinstance(value, str):
         # Replace ALL occurrences of problematic characters in the tag
diff --git a/unittests/test_validators.py b/unittests/test_validators.py
new file mode 100644
index 00000000000..9a98974e28c
--- /dev/null
+++ b/unittests/test_validators.py
@@ -0,0 +1,32 @@
+from django.core.exceptions import ValidationError
+
+from dojo.validators import clean_tags
+from unittests.dojo_test_case import DojoTestCase
+
+
+class TestCleanTags(DojoTestCase):
+
+    def test_clean_tags_string(self):
+        self.assertEqual("simple_tag", clean_tags("simple tag"))
+
+    def test_clean_tags_list(self):
+        self.assertEqual(["tag_one", "tag_two"], clean_tags(["tag one", "tag,two"]))
+
+    def test_clean_tags_empty_values(self):
+        self.assertEqual([], clean_tags([]))
+        self.assertEqual("", clean_tags(""))
+        self.assertIsNone(clean_tags(None))
+
+    def test_clean_tags_list_with_none_entries(self):
+        """
+        Parsers can emit None tags (e.g. Trivy legacy reports without a
+        "Class" field). clean_tags must filter them out instead of raising
+        TypeError from the regex (see import pipeline crash in
+        default_importer._process_findings_internal).
+        """
+        self.assertEqual(["os-pkgs"], clean_tags(["os-pkgs", None]))
+        self.assertEqual([], clean_tags([None, None]))
+
+    def test_clean_tags_invalid_type_raises(self):
+        with self.assertRaises(ValidationError):
+            clean_tags(42)
diff --git a/unittests/tools/test_trivy_parser.py b/unittests/tools/test_trivy_parser.py
index f43b079ea18..9aef80e263e 100644
--- a/unittests/tools/test_trivy_parser.py
+++ b/unittests/tools/test_trivy_parser.py
@@ -22,6 +22,10 @@ def test_legacy_many_vulns(self):
             parser = TrivyParser()
             findings = parser.get_findings(test_file, Test())
             self.assertEqual(len(findings), 93)
+            # Legacy reports have no "Class" field; tags must not contain None
+            # or the import pipeline crashes in clean_tags (TypeError)
+            for finding in findings:
+                self.assertNotIn(None, finding.unsaved_tags)
             finding = findings[0]
             self.assertEqual("Low", finding.severity)
             self.assertEqual(1, len(finding.unsaved_vulnerability_ids))