diff --git a/src/connection/Connection.ts b/src/connection/Connection.ts
index 54d0b2b..38969d0 100644
--- a/src/connection/Connection.ts
+++ b/src/connection/Connection.ts
@@ -92,6 +92,30 @@ export class Connection {
       this.isConnected = true;
     } catch (error) {
       logger.error("Failed to connect:", error);
+      // Tear down the half-open connection so its socket and event listeners
+      // don't leak when session setup (openSession/requestStatementId) fails
+      // after the TCP connection was already established. Mirrors close().
+      // Guard the teardown itself so a cleanup failure can't mask the
+      // original error that we rethrow below.
+      try {
+        if (this.connection) {
+          this.connection.removeAllListeners();
+          if (typeof this.connection.destroy === "function") {
+            this.connection.destroy();
+          } else {
+            this.connection.end();
+          }
+          this.connection = null;
+        }
+      } catch (cleanupError) {
+        logger.warn("Error during connection teardown:", cleanupError);
+      }
+      this.client = null;
+      // Mirror close(): clear session/statement ids so a failed setup does
+      // not leave a stale sessionId reachable via getSessionId().
+      this.sessionId = null;
+      this.statementId = null;
+      this.isConnected = false;
       throw error;
     }
   }
diff --git a/tests/unit/Connection.test.ts b/tests/unit/Connection.test.ts
index 26eca2d..7d5b01b 100644
--- a/tests/unit/Connection.test.ts
+++ b/tests/unit/Connection.test.ts
@@ -129,4 +129,68 @@ describe("Connection", () => {
 
     await connection.close();
   });
+
+  test("Should tear down the socket when session setup fails", async () => {
+    // openSession rejects after the TCP connection was established.
+    thriftMock.createClient.mockReturnValueOnce({
+      openSession: jest.fn((_req: unknown, callback: (e: Error | null, r: unknown) => void) =>
+        callback(new Error("auth failed"), null),
+      ),
+      requestStatementId: jest.fn((_sid: unknown, callback: (e: Error | null, r: unknown) => void) =>
+        callback(null, 456),
+      ),
+      closeSession: jest.fn((_req: unknown, callback: (e: Error | null, r: unknown) => void) =>
+        callback(null, { status: { code: 200 } }),
+      ),
+    });
+
+    const config: InternalConfig = {
+      host: "localhost",
+      port: 6667,
+      username: "root",
+      password: "bad",
+      enableSSL: false,
+      sqlDialect: "tree",
+    };
+    const connection = new Connection(config);
+
+    // The original setup error must surface, not be masked by the teardown.
+    await expect(connection.open()).rejects.toThrow("auth failed");
+
+    // The half-open connection must be torn down (mirrors close()); the buggy
+    // catch only logged + rethrew, leaking the socket and its listeners.
+    expect(thriftMock.__mockConnection.removeAllListeners).toHaveBeenCalled();
+    expect(thriftMock.__mockConnection.destroy).toHaveBeenCalled();
+  });
+
+  test("Should clear sessionId when statement setup fails after openSession", async () => {
+    // openSession succeeds (sets sessionId), then requestStatementId rejects.
+    thriftMock.createClient.mockReturnValueOnce({
+      openSession: jest.fn((_req: unknown, callback: (e: Error | null, r: unknown) => void) =>
+        callback(null, { status: { code: 200 }, sessionId: 123 }),
+      ),
+      requestStatementId: jest.fn((_sid: unknown, callback: (e: Error | null, r: unknown) => void) =>
+        callback(new Error("statement setup failed"), null),
+      ),
+      closeSession: jest.fn((_req: unknown, callback: (e: Error | null, r: unknown) => void) =>
+        callback(null, { status: { code: 200 } }),
+      ),
+    });
+
+    const config: InternalConfig = {
+      host: "localhost",
+      port: 6667,
+      username: "root",
+      password: "root",
+      enableSSL: false,
+      sqlDialect: "tree",
+    };
+    const connection = new Connection(config);
+
+    await expect(connection.open()).rejects.toThrow("statement setup failed");
+
+    // The failed setup must not leave a stale sessionId reachable (mirrors
+    // close()); getSessionId() throws once the id is cleared.
+    expect(() => connection.getSessionId()).toThrow("Session is not open");
+  });
 });