diff --git a/crates/vm/src/builtins/traceback.rs b/crates/vm/src/builtins/traceback.rs
index a91ec13c86f..2c3ab56229a 100644
--- a/crates/vm/src/builtins/traceback.rs
+++ b/crates/vm/src/builtins/traceback.rs
@@ -92,7 +92,10 @@ impl Py<PyTraceback> {
                 }
             }
         }
-        *zelf.next.lock() = value;
+        // Dropping the old chain can finalize a frame whose locals reenter
+        // this traceback. Publish the replacement before releasing the lock.
+        let old = core::mem::replace(&mut *zelf.next.lock(), value);
+        drop(old);
         Ok(())
     }
 }
diff --git a/crates/vm/src/exceptions.rs b/crates/vm/src/exceptions.rs
index 774e6e55745..178f88dbc82 100644
--- a/crates/vm/src/exceptions.rs
+++ b/crates/vm/src/exceptions.rs
@@ -743,18 +743,30 @@ impl PyBaseException {
 }
 
 impl PyBaseException {
+    // Replaced references may run Python finalizers. Release their locks
+    // before dropping the old values so those finalizers can reenter safely.
     pub fn set_traceback(&self, traceback: Option<PyTracebackRef>) {
-        *self.traceback.write() = traceback;
+        let old = core::mem::replace(&mut *self.traceback.write(), traceback);
+        drop(old);
     }
 
     pub fn set_cause(&self, cause: Option<PyRef<Self>>) {
-        let mut c = self.cause.write();
-        self.set_suppress_context(true);
-        *c = cause;
+        let old = {
+            let mut current = self.cause.write();
+            self.set_suppress_context(true);
+            core::mem::replace(&mut *current, cause)
+        };
+        drop(old);
     }
 
     pub fn set_context(&self, context: Option<PyRef<Self>>) {
-        *self.context.write() = context;
+        let old = core::mem::replace(&mut *self.context.write(), context);
+        drop(old);
+    }
+
+    fn set_args_tuple(&self, args: PyTupleRef) {
+        let old = core::mem::replace(&mut *self.args.write(), args);
+        drop(old);
     }
 
     pub(super) fn __suppress_context__(&self) -> bool {
@@ -873,7 +885,7 @@ impl Py<PyBaseException> {
         };
         let args: ArgIterable = value.try_into_value(vm)?;
         let args = args.iter(vm)?.collect::<PyResult<Vec<_>>>()?;
-        *self.args.write() = PyTuple::new_ref(args, &vm.ctx);
+        self.set_args_tuple(PyTuple::new_ref(args, &vm.ctx));
         Ok(())
     }
 
@@ -958,7 +970,7 @@ impl Py<PyBaseException> {
 impl PyRef<PyBaseException> {
     #[pymethod]
     fn with_traceback(self, tb: Option<PyTracebackRef>) -> Self {
-        *self.traceback.write() = tb;
+        self.set_traceback(tb);
         self
     }
 }
@@ -984,7 +996,7 @@ impl Initializer for PyBaseException {
     type Args = FuncArgs;
 
     fn init(zelf: &Py<Self>, args: Self::Args, vm: &VirtualMachine) -> PyResult<()> {
-        *zelf.args.write() = PyTuple::new_ref(args.args, &vm.ctx);
+        zelf.set_args_tuple(PyTuple::new_ref(args.args, &vm.ctx));
         Ok(())
     }
 }