diff --git a/python/sglang/srt/mem_cache/mamba_radix_cache.py b/python/sglang/srt/mem_cache/mamba_radix_cache.py
index 81d421613..3ca653872 100644
--- a/python/sglang/srt/mem_cache/mamba_radix_cache.py
+++ b/python/sglang/srt/mem_cache/mamba_radix_cache.py
@@ -204,6 +204,9 @@ class LRUList:
         setattr(
             getattr(node, self.nxt), self.prv, getattr(node, self.prv)
         )  # node.next.prev = node.prev
+        # Clear self pointers to break reference cycles among evicted nodes.
+        setattr(node, self.prv, None)
+        setattr(node, self.nxt, None)
 
     def _get_lru(self) -> Optional[TreeNode]:
         """
diff --git a/python/sglang/srt/mem_cache/swa_radix_cache.py b/python/sglang/srt/mem_cache/swa_radix_cache.py
index 4aa5edc0e..dd76ad37d 100644
--- a/python/sglang/srt/mem_cache/swa_radix_cache.py
+++ b/python/sglang/srt/mem_cache/swa_radix_cache.py
@@ -157,6 +157,9 @@ class LRUList:
         setattr(
             getattr(node, self.nxt), self.prv, getattr(node, self.prv)
         )  # node.next.prev = node.prev
+        # Clear self pointers to break reference cycles among evicted nodes.
+        setattr(node, self.prv, None)
+        setattr(node, self.nxt, None)
 
     def _get_lru(self) -> Optional[TreeNode]:
         """
diff --git a/python/sglang/srt/mem_cache/unified_radix_cache.py b/python/sglang/srt/mem_cache/unified_radix_cache.py
index 2fb7d45f9..d16b41603 100644
--- a/python/sglang/srt/mem_cache/unified_radix_cache.py
+++ b/python/sglang/srt/mem_cache/unified_radix_cache.py
@@ -124,6 +124,9 @@ class UnifiedLRUList:
         pt = self._pt
         node.lru_prev[pt].lru_next[pt] = node.lru_next[pt]
         node.lru_next[pt].lru_prev[pt] = node.lru_prev[pt]
+        # Clear self pointers to break reference cycles among evicted nodes.
+        node.lru_prev[pt] = None
+        node.lru_next[pt] = None
 
     def insert_mru(self, node: UnifiedTreeNode):
         assert node.id not in self.cache