diff --git a/cyclonedx/model/vulnerability.py b/cyclonedx/model/vulnerability.py
index 5f3bf024..1fc23673 100644
--- a/cyclonedx/model/vulnerability.py
+++ b/cyclonedx/model/vulnerability.py
@@ -36,14 +36,6 @@
 from enum import Enum
 from typing import Any, Optional, Union
 
-if sys.version_info >= (3, 13):
-    from warnings import deprecated
-else:
-    from typing_extensions import deprecated
-
-import py_serializable as serializable
-from sortedcontainers import SortedSet
-
 from .._internal.bom_ref import bom_ref_from_str as _bom_ref_from_str
 from .._internal.compare import ComparableTuple as _ComparableTuple
 from ..exception.model import MutuallyExclusivePropertiesException, NoPropertiesProvidedException
@@ -59,6 +51,19 @@
 )
 from .tool import Tool, ToolRepository, _ToolRepositoryHelper
 
+if sys.version_info >= (3, 13):
+    from warnings import deprecated
+else:
+    from typing_extensions import deprecated
+
+import py_serializable as serializable
+from sortedcontainers import SortedSet
+
+_RE_CVSS_V4 = re.compile(r'^CVSS:4\.\d/?')
+_RE_CVSS_V3 = re.compile(r'^CVSS:3\.\d/?')
+_RE_CVSS_V2 = re.compile(r'^CVSS:2\.\d/?')
+_RE_OWASP = re.compile(r'^OWASP/?')
+
 
 @serializable.serializable_class(ignore_unknown_during_deserialization=True)
 class BomTargetVersionRange:
@@ -643,15 +648,15 @@ def get_localised_vector(self, vector: str) -> str:
             The vector without any scheme prefix as a `str`.
         """
         if self is VulnerabilityScoreSource.CVSS_V4 and vector.startswith('CVSS:4.'):
-            return re.sub(r'^CVSS:4\.\d/?', '', vector)
+            return _RE_CVSS_V4.sub('', vector)
         if (
             self in (VulnerabilityScoreSource.CVSS_V3_1, VulnerabilityScoreSource.CVSS_V3)
         ) and vector.startswith('CVSS:3.'):
-            return re.sub(r'^CVSS:3\.\d/?', '', vector)
+            return _RE_CVSS_V3.sub('', vector)
         if self is VulnerabilityScoreSource.CVSS_V2 and vector.startswith('CVSS:2.'):
-            return re.sub(r'^CVSS:2\.\d/?', '', vector)
+            return _RE_CVSS_V2.sub('', vector)
         if self is VulnerabilityScoreSource.OWASP and vector.startswith('OWASP'):
-            return re.sub(r'^OWASP/?', '', vector)
+            return _RE_OWASP.sub('', vector)
         return vector
 
     def get_value_pre_1_4(self) -> str: